Electromagnetic vibrator

An electromagnetic vibrator comprising:

• a housing having a cover;
• a striker mounted within said housing for reciprocable movement therein;
• and
• an excitation coil fixedly mounted in said housing, said excitation coil having a base and a central, longitudinal axis and said excitation coil producing an alternating magnetic field to cause the striker to reciprocate along the central, longitudinal axis of the excitation coil;
• the improvement being that:
• the striker is arranged to freely reciprocate within the housing and includes a permanent magnet having an end surface in a plane parallel to said base of said excitation coil, said end surface being located at a distance within the range of 0.6 to 0.7 of the height of the excitation coil with respect to said base of the excitation coil;
• and
• a second permanent magnet is secured in the cover of the housing and interacts with the permanent magnet of the striker in order to produce a magnetic field directed along the axis of the striker and in opposition to the magnetic field of the permanent magnet of the striker.