Patent ID: 8917089

Claim:
A device for detecting metal plate elements configured to work with or to be incorporated into a system for selection, movement, transfer and/or positioning of the metal plate elements, the device comprising: an emission coil supplied by suitable control means and generating a magnetic field; at least one reception coil disposed to generate by induction a voltage signal at terminals of the at least one reception coil as a result of the generation of the magnetic field; and means for processing and evaluating the voltage signal provided by the at least one reception coil to provide an informative signal indicating an absence or a presence of one or more of the metal plate elements in the vicinity of the emission and reception coils, the emission and reception coils being positioned spaced apart and with a specific mutual inclination such that the magnetic coupling between the emission and reception coils is changed by the presence of the one or more metal plate elements, wherein the emission coil and the at least one reception coil are both mounted in a case or a sensor head having an active detection face with a corresponding detection area, the emission and reception coils being positioned with the specific mutual inclination in relation to one another and in relation to the detection face, the emission and reception coils being arranged according to a configuration such that, seen in section along a plane containing their respective axes of symmetry, the emission and reception coils form with the active detection face approximately a right triangle, the active detection face constituting the hypotenuse, the emission and reception coils partly forming the two other sides of the triangle, the detection area being situated outside of the triangle, and a magnitude of change in amplitude and/or in power of a voltage signal at terminals of the at least one reception coil due to the presence of a peripheral part or of an edge of the one or more metal elements near the active detection face is recognized and used in a discrete manner by the processing and evaluating means to determine the number of the one or more metal plate elements that are present, a coupling intensity between the emission and reception coils being correspondingly reduced in accordance with the presence of an increasing number of metal plate elements in the detection area.