Electromagnetic hydraulic valve operator

An electromagnetically actuated hydraulic switch, comprising:

• a housing;
• hydraulic valve means in said housing, including bistable snap blade means operable between different hydraulic circuit positions;
• and
• electromagnetic actuator means mounted in said housing for actuating said snap blade means,
• wherein said electromagnetic actuator means comprises coil means energizable to create magnetic flux, yoke means for directing the flux path of said coil means, and movable armature means responsive to energization of said coil means to actuate said snap blade means, and
• wherein said housing includes a cavity into which a portion of armature means extends and engages said snap blade means, said armature means including a plunger reciprocal in a journaled portion of said housing, and including a hydraulic fluid entry port into said cavity, a hydraulic fluid exit port out of said cavity, and a hydraulic fluid vent port out of said cavity, said snap blade means in a first position blocking said vent port and opening said entry port such that hydraulic fluid may flow from said entry port to said exit port, said snap blade means in a second position blocking said entry port such that hydraulic fluid may flow from said exit port to said vent port, wherein said bistable snap blade means comprises a flexible member rigidly mounted at one end in said housing and having a hydraulic valve contact at the other end, and including a pair of wire-like cantilever arms each extending from a respective one of said ends towards each other to a gap therebetween to be engaged by said armature means, and wherein said ends are connected by a pair of wire-like outer side segments, said wire-like cantilever arms extending between and parallel to said wire-like outer side segments.

An electromagnetically actuated hydraulic switch, comprising:

• a housing;
• hydraulic valve means in said housing, including bistable snap blade means operable between different hydraulic circuit positions;
• and
• electromagnetic actuator means comprising an armature plunger axially reciprocally shuttling between closed loop returned magnetic paths provided by a pair of coaxial coils energizable to create magnetic fluxes having portions of their linkage paths in common including through said plunger, such that when either coil is energized a flux path is created around that coil through the plunger, and another flux path is created around both coils through the plunger, and comprising permeance control means including magnetically continuous yoke means controlling the ratio of permeances of the two paths such that one path always overpowers the other, to insure plunger movement in either direction for actuating said snap blade means, the flux paths from the axial ends of said plunger extending substantially only axially to said yoke means, said yoke means having a central leg extending radially between said coils, said leg having an inner end facing said plunger and separated therefrom by a radial gap, the axial length of said radial gap being no greater than the axial spacing of said coils.

An electromagnetically actuated hydraulic switch, comprising:

• a housing;
• hydraulic valve means in said housing including bistable snap blade means operable between different hydraulic circuit positions, and including hydraulic port means in said housing engaged by said snap blade means;
• and
• electromagnetic actuator means comprising an armature plunger axially reciprocally shuttling between closed loop returned magnetic paths having common overlapping portions through the plunger provided by yoke means directing the flux paths of a pair of coils such that when either coil is energized a first flux path is created around that coil through the plunger and a second flux path is created around both coils through the plunger, the first path pulling the plunger to close a magnetic air gap, the second path holding the plunger in place, the ratio of the permeances of the two paths being controlled such that one path always overpowers the other, to insure plunger movement in either direction for actuating said snap blade means, said snap blade means extending transversely to the axial movement of said plunger and having a distal end with a hydraulic contact laterally offset from the axis of reciprocation of said plunger and movable between said different hydraulic circuit positions engaging respective said port means, wherein said coils are coaxial and said yoke means is magnetically continuous, the flux paths from the axial ends of said plunger extending substantially only axially to said yoke means, said yoke means having a central leg extending radially between said coils, said leg having an inner end facing said plunger and separated therefrom by a radial gap, the axial length of said radial gap being no greater than the axial spacing of said coils.

An electromagnetically actuated hydraulic switch comprising:

• a housing having a cavity with hydraulic port means;
• hydraulic valve means in said housing, including bistable snap blade means in said cavity and operable between different hydraulic circuit positions to engage said hydraulic port means for opening and blocking the latter;
• a pair of coils coaxially mounted in said housing and energizable to create magnetic flux;
• magnetically continuous yoke means in said housing for directing the flux paths of said coils in closed loop returned paths through portions of common overlapping flux linkage;
• and
• an armature shuttle plunger axially reciprocal in a journaled portion of said housing according to energization of a respective said coil such that when either coil is energized a flux path is created around that coil through the plunger and another flux path is created around both coils through the plunger, the flux paths from the axial ends of said plunger extending substantially only axially to said yoke means, said yoke means having a central leg extending radially between said coils, said leg having an inner end facing said plunger and separated therefrom by a radial gap, the axial length of said radial gap being no greater than the axial spacing of said coils, said yoke means controlling the ratio of the permeances of the two paths such that one path always overpowers the other, to insure plunger movement in either direction for actuating said snap blade means.

An electromagnetically actuated hydraulic switch, comprising:

• a housing having a cavity with hydraulic ports;
• hydraulic valve means in said housing, including bistable snap blade means in said cavity and operable between different hydraulic circuit positions for engaging said hydraulic ports for opening and blocking the latter;
• first and second coaxial coils in said housing energizable to create magnetic flux;
• magnetically continuous yoke means in said housing for directing the flux of said coils in partially overlapping closed loop returned paths;
• an armature shuttle plunger in said housing axially reciprocal between first and second positions respectively closing and opening first and second axial gaps between said plunger and said yoke means, said plunger being in said overlapping flux paths in each of said first and second positions, reciprocation of said plunger actuating said snap blade means, said snap blade means extending transversely to the axial movement of said plunger and having a distal end with a hydraulic contact laterally offset from the axis of reciprocation of said plunger and movable between said different hydraulic circuit positions engaging respective said ports,
• energization of said first coil creating a primary flux around the latter attracting said plunger to said first position to close said first gap and open said second gap, and creating a secondary flux around both said coils attracting said plunger to remain in said first gap open energization of said second coil creating a primary flux around the latter attracting said plunger to said second position to close said second gap and open said first gap, and creating a secondary flux around both said coils attracting said plunger to remain in said first position with said first gap closed and said second gap open the flux paths from the axial ends of said plunger extending substantially only axially to said yoke means, said yoke means having a central leg extending radially between said coils, said leg having an inner end facing said plunger and separated therefrom by a radial gap, the axial length of said radial gap being no greater than the axial spacing of said coils the force on said plunger from said primary flux around either said coil always being stronger than the force on said plunger from said secondary flux, such that said plunger moves in either direction responsive to the primary flux in the open gap and actuates said snap blade means.

An electromagnetically actuated hydraulic switch, comprising:

• a housing having a cavity with hydraulic ports;
• hydraulic valve means in said housing, including bistable snap blade means in said cavity and operable between different hydraulic circuit positions of engaging said hydraulic ports for opening and blocking the latter;
• first and second coils in said housing energizable to create magnetic flux;
• yoke means in said housing for directing the flux of said coils in partially overlapping closed loop returned paths;
• an armature shuttle plunger in said housing reciprocal between first and second positions respectively closing and opening first and second gaps between said plunger and said yoke means, said plunger being in said overlapping flux paths in each of said first and second positions, reciprocation of said plunger actuating said snap blade means,
• energization of said first coil creating a primary flux around the latter attracting said plunger to said first position to close said first gap and open said second gap, and creating a secondary flux around both said coils attracting said plunger to remain in said second position with said second gap closed and said first gap open, energization of said second coil creating a primary flux around the latter attracting said plunger to said second position to close said second gap and open said first gap, and creating a secondary flux around both said coils attracting said plunger to remain in said first position with said first gap closed and said second gap open, the force on said plunger from said primary flux around either said coil always being stronger than the force on said plunger from said secondary flux such that said plunger moves in either direction responsive to the primary flux in the open gap and actuates said snap blade means, wherein said snap blade means comprises a flexible member rigidly mounted at one end in said housing and having a hydraulic contact at the other end, and including a pair of cantilever arms each extending from a respective one of said ends towards each other to a gap therebetween, said plunger engaging said cantilever arms in actuating relation to flex said snap blade means between bistable overcenter snap-action positions, said cantilever arms being bowed in one direction in a first stable position and being bowed in the opposite direction in the alternate stable position.

An electromagnetically actuated hydraulic switch, comprising:

• a housing;
• hydraulic valve means in said housing, including bistable snap blade means operable between different hydraulic circuit positions;
• a pair of coils coaxially mounted in said housing and energizable to create magnetic flux;
• magnetically continuous yoke means in said housing for directing the flux paths of said coils;
• and
• a shuttle plunger axially reciprocal in said housing between first and second positions according to energization of a respective said coil providing a primary flux path around the respective said coil through said yoke means and said plunger, and providing a secondary flux path around both said coils through said yoke means and said plunger, such that the primary path flux force around either coil is always stronger than the secondary path, the flux paths from the axial ends of said plunger extending substantially only axially to said yoke means, said yoke means having a central leg extending radially between said coils, said leg having an inner end facing said plunger and separated therefrom by a radial gap, the axial length of said radial gap being no greater than the axial spacing of said coils, said plunger engaging said snap blade means in actuating relation to operate the latter between said hydraulic circuit positions corresponding to said first and second positions of said plunger.

An electromagnetically actuated hydraulic switch, comprising:

• a housing;
• hydraulic valve means in said housing, including bistable snap blade means operable between different hydraulic circuit positions;
• a pair of coils coaxially mounted in said housing and energizable to create magnetic flux;
• yoke means in said housing for directing the flux paths of said coils;
• and
• a shuttle plunger axially reciprocal in said housing between first and second positions according to energization of a respective said coil providing a primary flux path around the respective said coil through said yoke means and said plunger, and providing a secondary flux path around both said coils through said yoke means and said plunger, such that the primary path flux force around either coil is always stronger than the secondary path, said plunger engaging said snap blade means in actuating relation to operate the latter between said hydraulic circuit positions corresponding to said first and second positions of said plunger;
• said yoke means includes first and second axially spaced stop shoulders for limiting said axial movement of said plunger at respective said first and second positions corresponding to said hydraulic circuit positions of said snap blade means.
• said yoke means includes a central portion between said coils and spaced from said plunger;
• such that when said plunger is in said second position and said first coil is energized, said primary flux path extends around said first coil through said yoke means and across an axial gap between said first stop shoulder of said yoke means and said plunger and through said plunger and across a radial gap between said plunger and said central portion of said yoke means, and said secondary path extends around both said coils through said yoke means and across an axial gap between said first stop shoulder of said yoke means and said plunger and through said plunger and through said second stop shoulder of said yoke means;
• and
• such that when said plunger is in said first position and said second coil is energized, said primary flux path extends around said second coil through said armature means and across an axial gap between said second stop shoulder of said yoke means and said plunger and through said plunger and across said radial gap between said plunger and said central portion of said yoke means, and said secondary path extends around both said coils through said yoke means and across said axial gap between said second stop shoulder of said yoke means and said plunger and through said plunger and through said first stop shoulder of said yoke means,
• wherein said snap blade means comprises a flexible member rigidly mounted at one end in said housing and having a hydraulic contact at the other end, and including a pair of cantilever arms each extending from a respective one of said ends towards each other to a gap therebetween, said plunger engaging said cantilever arms in actuating relationship to flex said snap blade means between bistable overcenter snap-action positions, said cantilever arms being bowed in one direction in a first stable position and being bowed in the opposite direction in the other alternate stable position.

An electromagnetically actuated hydraulic switch, comprising:

• a housing;
• hydraulic valve means in said housing, including bistable snap blade means comprising a flexible member rigidly mounted at one end in said housing and having a hydraulic contact at the other end, and including a pair of cantilever arms each extending from a respective one of said ends towards each other to a gap therebetween;
• and
• magnetic actuator means mounted in said housing and extending into said gap and engaging said cantilever arms to actuatingly flex said snap blade means between bistable overcenter snap-action positions.

An electromagnetically actuated bistable hydraulic switch combination with zero holding energy, comprising:

• a housing;
• hydraulic valve means in said housing, including bistable snap blade means operable between different hydraulic circuit positions, and comprising a flexible member rigidly mounted at one end in said housing and having a hydraulic contact at the other end, and including a pair of cantilever arms each extending from a respective one of said ends towards each other to a gap between;
• a pair of coils coaxially mounted in said housing and energizable to create magnetic flux;
• yoke means in said housing for directing the flux paths of said coils;
• and
• a shuttle plunger axially reciprocal in said coils between first and second positions according to energization of a respective said coil providing a primary flux path around the respective said coil through said yoke means and said plunger, and providing a secondary flux path around both said coils through said yoke means and said plunger, such that the primary path flux force around either coil is always stronger than the secondary path flux force.

An electromagnetically actuated hydraulic switch combination, comprising:

• a housing;
• hydraulic valve means in said housing including bistable snap blade means operable between different hydraulic circuit positions;
• a pair of coaxial coils in said housing energizable to create magnetic flux;
• a shuttle plunger in said housing axially reciprocal between first and second positions to actuate said snap blade means, said snap blade means extending transversely to the axial movement of said plunger and having a distal end laterally offset from the axis of reciprocation of said plunger and movable between different hydraulic circuit positions;
• magnetically continuous yoke means in said housing for directing the flux paths of said coils, said yoke means having a first portion spaced from said plunger by a first axial gap when said plunger is in said second position, said yoke means having a second portion spaced from said plunger by a second axial gap when said plunger is in said first position, said yoke means having a third portion spaced from said plunger by a third gap in each of said first and second plunger positions;
• such that when said plunger is in said second position and said first coil is energized, a primary flux path is created and extends around said first coil through said yoke means and said plunger and across said first and third gaps, and a secondary flux path is created and extends around both said coils through said yoke means and said plunger and across said first gap, said primary path flux force attracting said plunger to said first position to close said first gap, said secondary path flux force attracting said plunger to remain in said second position;
• and
• such that when said plunger is in said first position and said second coil is energized, a primary flux path is created and extends around said second coil through said yoke means and said plunger and across said second and third gaps, and a secondary flux path is created and extends around both said coils through said yoke means and said plunger and across said second gap, said last mentioned primary path flux force attracting said plunger to said second position to close said second gap, said last mentioned secondary path flux force attracting said plunger to remain in said first position, the flux paths from the axial ends of said plunger extending substantially only axially to said yoke means, said third portion of said yoke means being a central leg extending radially between said coils, said leg having an inner end facing said plunger and separated therefrom by a radial said third gap, the axial length of said radial gap being no greater than the axial spacing of said coils, the force on said plunger from said primary flux around either said coils always being stronger than the force on said plunger from said secondary flux, such that said plunger moves in either direction responsive to the primary flux in the open gap and actuates said snap blade means.