摘要 |
A magnetic snap latch having a coil (4) wound on a preformed insulating bobbin (3) having anti-rotation projections (3a) that locate and fix the coil within a high permeability magnetic shell (2). A high permeability magnetic plunger (1) extends through a hole (2a) in the shell into the coil (4) and has rigidly secured thereto a low permeability magnetic disk (6) within the shell. A high permeability backplate (5) closes the open end of the shell and defines an air gap (AG2) in which is located a non-magnetic return spring (7). When the coil is energized, the disk (6) is initially attracted to the shell (2) to move the plunger (1) a small distance to the right but the disk (6) then saturates and the increasing magnetic force in the air gap (AG2) snaps the plunger (1) to the left, whereafter the return spring (7) restores the plunger (1) when the coil (4) is deenergized.
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