INERTIA SWITCH Russian patent published in 1999 - IPC

FIELD: electromechanical threshold-action inertial sensors. SUBSTANCE: switch case accommodates contact pair with flexible contact member, spherical inertial body made of magnetically permeable material, permanent magnet that holds inertial body in initial position, and facility concentrating magnetic field along inertial body travel. Flexible structural member is, essentially, cantilever beam carrying permanent magnet on its fastening end; inertial body is installed for displacement over surface of mentioned beam both lengthwise and in direction of displacement of its contacting end; magnetic field concentrating facility is built up of two pole shoes placed on either side of mentioned cantilever beam in parallel to its plane of bending; each pole shoe abuts against respective pole end of permanent magnet. Magnetizing axis of permanent magnet is perpendicular to direction of inertial body displacement; pole shoes are made in the form of plates covering displacement length of inertial body, their width reducing lengthwise of cantilever beam towards its contacting end. When in initial position, inertial body resides in taper or wedge-shaped seat formed by lugs of second contact pair. Adjusting screw made of magnetically permeable material is installed in case between permanent magnet and mentioned seat. Switch mounted in moving equipment operates under the impact of two inertial force components, that is, axial force due to variations in linear velocity of equipment and centrifugal force due to equipment torsion relative to longitudinal axis. EFFECT: improved reliability and electric circuit switching characteristics, simplified design, reduced size, enlarged functional capabilities. 4 cl, 2 dwg