Bistable electromagnetic actuator
AssigneeRegdon Corporation
InventorReginald A. Read, Jr.
Life of this patent
Estimating the term…
Abstract
An actuator having an armature plate urged to a stable position by a spring and which may be held in another stable position by a permanent magnet. Application of an appropriate current pulse to a coil within the actuator reduces the flux flow through and the magnetic force on the armature sufficiently to release the armature to the former stable position under the influence of the spring. Two magnetic circuits, one of which includes a non-working air gap, are employed, the non-working air gap serving to maintain a flux path, of a predetermined maximum reluctance, for the permanent magnet when the armature plate is in the former stable position.
Claims13
Magnetic apparatus comprising:
- a hollow housing of highly magnetically permeable material, having a principal axis and an inner wall, said housing being closed at one end;
- a magnet in in close magnetic contact with said closed end of said housing, and substantially axially aligned with said principal axis, said magnet forming a gap of at least a first dimension with said inner wall;
- a shunt piece, of highly magnetically permeable material, in close magnetic contact with said magnet and substantially axially aligned with said principal axis, said shunt piece forming a gap with said inner wall of substantially a second dimension, said second dimension being less than said first dimension;
- a coil;
- a core, of highly permeable magnetic material, in close magnetic contact with said shunt piece and substantially axially aligned with said principal axis, said coil being disposed about said core and said core including a portion extending axially beyond said coil;
- a pole piece, of highly magnetically permeable material, disposed adjacent said coil and about that portion of said core extending beyond said coil, in close magnetic contact with said inner wall of said housing and forming a gap between an inner surface of said pole piece and said portion of said core;
- armature means, including an armature plate, of highly magnetically permeable material, disposed for reciprocal movement in said housing between first and second positions, along said principal axis, said plate being disposed to overlie, in close magnetic contact, said core and said pole piece in said first position, and to have a gap of at least a third dimension with at least one of said pole piece and said core in said second position;
- and
- means for urging said armature plate to said second position.
Dependencies are inferred from the claim text.