Electromagnetic injectors

Claim 2

A fuel injector for internal combustion engines of the type comprising a cylindrical casing, fuel feed means, coil induction means, an injection nozzle enclosing an injection needle-valve, a pallet attracted at each injection cycle by said coil induction means and located in said casing for controlling the injection, wherein a fuel metering calibrated aperture is formed in the upper face of the injection nozzle facing a plane face of the pallet constituting a plane closure member, the injection needlevalve having a head at its end opposed to the calibrated aperture cooperative with a seat which puts the injection nozzle in communication with the exterior of the injector, said needlevalve being biased in contact with said seat by a calibrated spring for controlling the fuel pressure downstream of the metering aperture which pressure is substantially lower than the fuel feed pressure.

Claim 3

A fuel injector as claimed in claim 1, wherein the metering aperture is surrounded by a continuous rib, which is coaxial with said aperture and spaced from the edge of the aperture.

Claim 4

A fuel injector as claimed in claim 2, wherein said continuous rib is surrounded by a concentric rib having a larger diameter and the same height, said concentric rib having at least one gap for the passage of the fuel.

Claim 5

A fuel injector for internal combustion engines comprising a casing, an injector nozzle having a substantially closed end disposed in the casing and an opposite external end, a bore in the injection nozzle open at said external end and terminating short of the closed end of the nozzle, fuel feed means through the casing, an aperture through said closed end conneCting said bore and said fuel means, a pallet having a face adapted to combine with said closed end to block fuel flow through the aperture, means for biasing the pallet into blocking relationship with the closed end, an induction coil in said casing adapted to attract and move the pallet against the biasing action from said blocking relationship, piston means slideable in said bore carrying means for closing the said open end of the bore, means for biasing said piston into closing relationship with the said open end when the aperture is closed by the pallet but responsive to said fluid pressure to move from its closing position when the pallet is biased away from the aperture.

Claim 6

A fuel injector for internal combustion engines comprising a casing, an injector nozzle having a substantially closed end disposed in the casing and an opposite external end, a bore in the injection nozzle open at said external end and terminating short of the closed end of the nozzle, fuel feed means through the casing, an aperture through said closed end conneCting said bore and said fuel means, a pallet having a face adapted to combine with said closed end to block fuel flow through the aperture, means for biasing the pallet into blocking relationship with the closed end, an induction coil in said casing adapted to attract and move the pallet against the biasing action from said blocking relationship, piston means slideable in said bore carrying means for closing the said open end of the bore, means for biasing said piston into closing relationship with the said open end when the aperture is closed by the pallet but responsive to said fluid pressure to move from its closing position when the pallet is biased away from the aperture.

Claim 7

The fuel injector of claim 4 wherein the said piston means is an elongated pin having a substantially conical end adjacent said aperture and an outwardly flared opposite end adapted to close the open end of the bore.

Claim 8

The fuel injector of claim 4 wherein a valve is disposed in said bore having a sleeve disposed snugly therein, a first bore in the sleeve communicating with the aperture, a counter-bore of greater cross-section communicating between the said first bore and the external end of the nozzle, a pin slideable in the first bore and counter-bore, a conical end carried by the pin adjacent to said aperture and means carried by the pin at its opposite end for closing the bore in the sleeve adjacent to the external end of the nozzle, and a spring biasing said opposite end of the pin into closing relationship with the said bore.

Claim 9

The fuel injector of claim 6 wherein the pin carries a piston adjacent its conical end and said spring is compressed between the piston and a shoulder formed by the bore and counter-bore of the sleeve.

Claim 10

The fuel injector of claim 6 wherein a first valve member is slideably disposed in the counter-bore, a second valve member is adjacent to said aperture, and a biasing spring is attached at its opposite ends to the valve members.

Claim 11

The injector of claim 4 wherein the surface of the said closed end carries a ring about the aperture and the said face of the pallet is disposed on the ring when the pallet is not attracted by the induction coil.