A vibratory atomizer for atomizing a liquid, which atomizer comprises a nozzle portion from which the liquid is ejected, a body portion having vibration means, and a liquid inlet pipe which is attached to the body portion and which is made a number of half wave lengths long for the speed of sound in the pipe whereby in use of the vibratory atomizer energy radiated into the pipe reflects back into the body portion in phase.

A device for metering liquids, which device comprises a body, a liquid conduit in the body, vibration means for vibrating the body, a valve for opening the conduit when the body is being vibrated and for closing the conduit when the body is not being vibrated, and a conduit external of the body and arranged to conduct liquid towards or away from the conduit in the body, the device being such that in operation liquid fed along one of the conduits is metered along the other conduit by activating the vibration means for a desired liquid metering time to cause the valve to open the conduit in the body.

A vibratory fuel atomizer in which a small housing is located within the atomizer near the atomizer tip, the housing containing a ball valve for shutting off the flow of fuel and a spring for biasing the ball valve to the closed position.

A single-point fuel injection system including an electromagnetically-operable ball valve injector. The injector comprises a hollow body which is surrounded by an annular gallery through which fuel is circulated under pressure continuously. Inlet ports are formed in the body whereby fuel from the gallery enters a chamber within the body in a direction transverse to the axis of the injector. The chamber communicates with the nozzle orifice via an aperture within which the ball valve is located. The difference between the diameter of the aperture and the diameter of the ball is sufficiently small to restrict fuel flow from the chamber to the nozzle orifice so that the valve is urged to seat and close the nozzle orifice by the differential fluid pressure loading on it.

A fuel injection nozzle arrangement comprising a fuel injection nozzle having a fuel injection orifice, and vibratory means such as a piezoelectric crystal for vibrating the nozzle to cause atomization of fuel ejected from the nozzle through the orifice, the nozzle having a fuel-retaining valve at the fuel inlet side of the orifice arranged to normally close the orifice and thus prevent the injection of fuel but to be opened when the vibratory means is energised to permit injection of fuel, and the nozzle having a gas-excluding valve at the fuel outlet side of the orifice arranged to normally close the orifice and thus prevent the entry of gases into the nozzle through the orifice but to open under fuel injection pressure to permit the injection of fuel.