Patent ID: 8622315

Claim:
A fluid injector comprising: a housing in which a pumping chamber is formed; a piston which is slidable axially in a bore in the housing to draw fluid into or force fluid out of the pumping chamber; an electrical coil for generating a field which forces the piston in a first direction; a biasing spring which acts on the piston to force the piston in a second direction opposite to the first direction; a fluid outlet; an annular gallery arranged to surround the fluid outlet; a fluid inlet which terminates in the annular gallery; a one-way inlet valve which allows fluid to be drawn into the pumping chamber from the fluid inlet while preventing fluid being expelled from the pumping chamber to the fluid inlet; a one-way outlet valve which allows fuel to be expelled from the pumping chamber to the fuel outlet while preventing fuel being drawn into the pumping chamber from the fluid outlet and; a valve seat comprising at least one orifice; wherein: the one-way inlet valve is a reed valve comprising: at least one reed valve blade, the or each reed valve blade having an annular valve head attached to at least one resilient spring arm, the or each valve head being operable to open and close the/an orifice in the valve seat; and a support for the or each reed valve blade, the or each spring arm extending inwardly from the support; and wherein: the or each spring arm is curved.