摘要 |
<p>An electromagnetic device includes a core and a coil in the space between a central section and an outer section of the core and spaced inwardly of an open side of the core such that the coil is completely recessed within the core. An armature, facing and aligned with the recess in the core is being movable towards and away from the coil. A pair of springs on the opposite ends of the core, and coaxial with the longitudinal axis of the core, mount the armature for straight-line reciprocatory movements parallel to the longitudinal axis of the core such that during the movement of the armature: (a) a recess in the armature receives the central section of the core; (b) the outer surface of the armature defines a first working gap with the inner surface of the core outer section; (c) and the inner surface of the armature at the recess defines a second working gap with the outer surface of the core central section.</p> |