53 a cover the remainder of the open face 32 a leaving minimal base 50 close to the valve stem 14 sockets 46 a are formed in the open face 32 of the core 28 and hold each of the windings of the coil 24 at their deepest portions and are shaped corresponding to the teeth 44 a referring to fig4 b in an alternative embodiment the teeth 44 b have hemicircular cross sections similar to the teeth of fig6 b as opposed to the trapezoidal cross sections as in the embodiment of fig2 the teeth 44 b flank the windings of the coil 24 so that the windings are positioned in between sockets 46 b in each of the embodiments of fig4 a and 4 b no change in the basic dimensions of the windings of coils 24 and 26 is required and they remain encased in the cores 28 and 30 referring now to fig5 the armature plate 34 may be asymmetric across a bisecting plane perpendicular to the valve stem 14 with the teeth 44 extending on only one side of the armature plate 34 toward sockets 46 on only one core 30 and wherein the opposite side of the armature plate 34 and its opposing core 28 is planar in this way armature mass is reduced and fabrication simplified while improved actuation force is provided toward core 30 which may preferably be the lower core of cores 28 and 30 allowing improved opening for.