Abstract: An electromagnetic fuel injector for use in an internal combustion engine has a center pole piece with an axially extending bore which slidingly accepts an adjusting pin therein. The adjusting pin has a first end portion for engagement with the armature return spring of the injector. Axial translation of the adjusting pin, relative to the center pole piece will vary the compression on the spring, the seating load on the armature valve and, as such, the dynamic flow characteristic of the injector. The adjusting pin further has means for engaging the center pole piece to rotate the piece which is threadingly engaged within the injector housing. Rotation of the threaded piece relative to the housing varies the armature/valve travel and, as such, the static flow characteristic of the injector.

Abstract: An electromagnetic actuator having an integral calibration mechanism for easy adjustment of armature response times. An additional (secondary) coil is incorporated into the device for providing a magnetic field opposing the magnetic field produced by the actuator's primary coil. A variable resistive element, used in conjunction with the secondary coil, provides a means for adjusting the current flow through the secondary coil and thereby the strength of the resultant magnetic field experienced by the armature. Since an is armature's response is proportional to the strength of the magnetic field to which it is subjected, this invention provides a means of calibrating the armature response times of an actuator. The availability of establishing a uniform, desired response results in improved multiple actuator system functionality and more reliable actuator interchangeability.