Abstract: Vibratory alertion of received messages to subscribers of low profile pagers can be achieved in the following manner. On the substrate, or pager housing, attaching a pivotal post and a bumper a predetermined distance from the pivotal post. Attaching a substantially planar polarizable material to the pivotal post such that the polarizable material is substantially parallel to the substrate and when in motion, moves substantially parallel to the substrate. The polarizable material is set in motion by an excitation winding which provides a varying field.

Abstract: An impulse transducer that does not use eccentric, motor-driven weights is constructed of a permanent magnet movable armature that oscillates within a housing and impacts resilient bumpers to produce vibrations. The armature is accelerated by a varying magnetic field energized by an alternating current. The dimensions of the enclosed housing and the mass of the movable armature as well as the strength of the magnetic fields can be optimized for the impulse magnitude that is desired.