Bistable fuel valve

Claim 1

A magnetically actuated bistable thruster valve assembly comprising, in combination: a permanent magnet assembly including a pair of spaced apart, plate-like permanent magnets disposed in similarly poled positions, first and second pole plates sandwiching said permanent magnets therebetween and forming therewith a generally enclosed space, and said pole plates having mutually spaced opposite end portions whereby to define air gaps therebetween; an armature disposed within said space and having opposite end portions respectively received in said gaps; flexure means within said space and connected substantially centrally to said armature for allowing said armature to rock between a first position in which one end thereof engages one pole plate while the other end engages the other pole plate to establish a flux field in one direction through the armature and a second position in which said one end thereof engages said one pole plate, said flexure means normally urging said armature to a neutral position between said first and second positions thereof and said permanent magnets having sufficient strength to retain said armature in either of its first and second positions, once attained; a pair of coils disposed in said space in surrounding relation to said armature for opposing, when sequentially energized, the respective flux field established in said armature by said permanent magnets whereby to allow said armature to be released from its first position and snap toward its second position and vice versa; pulsing means for periodically and transiently energizing said coils to oppose said flux fields for times sufficient to allow said armature to move from one position to the other; a valve block mounted below said pole plates and defining a valve chamber, means for delivering propellant under pressure into said chamber, and a pair of oppositely directed propellant outlets communicating with said chamber; a valve member connected to said armature and projecting downwardly from said space into said chamber, said valve member having two valves thereon for respectively closing off said propellant outlets when said armature is in its first and second positions; oppositely directed thruster means connected to said respective propellant outlets; and means for varying said pulsing means to control the net thrust produced by said thrusters.