Electro-pneumatic digital interface

Claim 1

An electric to pneumatic interface device for a fluid pressure system comprising: a. a pure fluid digital control device having first and second outputs, and a control port subject to variation of fluid pressure to control pressurization of said first and second outputs, b. electro-magnetic means including a magnetic core arranged with a selectively energized control winding, said core having a control passage extending therethrough communicated with said control port, and c. interrupter means comprising a flexible magnetic armature fixedly mounted at one end and selectively positionable with respect to said control passage to control fluid pressure therein in accordance with said armature opening said control port in one position responsive to one condition of energization of said winding and closing said control port in a second position responsive to a condition of energization of said winding opposite said one condition, said interrupter means further including a magnetic insulator carried by said armature when in said second position in spaced-apart relationship therewith sufficient to limit the residual magnetic force of attraction therebetween to a value less than the force of flexure of said armature.