Patent ID: 9421884
Filing Date: 2016-08-23
CPC Classification: B60N,B60R,G01G,G01L

Claim Text:
1. A pressure-responsive seat occupancy sensor unit for detecting an occupancy state of a seat, e.g. of a vehicle seat, comprising: a support plate with a support area; a pressure-responsive membrane switch arranged in said support area, said pressure-responsive membrane switch comprising a first carrier film and a second carrier film spaced from each other by a spacer film, said spacer film having therein an opening defining a cell, said pressure-responsive membrane switch comprising at least two electrodes arranged in facing relationship with each other in said cell on said first and said second carrier film, respectively, in such a way that they are brought closer together, possibly into contact with each other, when pressure is applied on said pressure-responsive membrane switch; one or more spacers arranged around said support area, said one or more spacers defining an upper surface raised with respect to said support area; a compressible foam comprising a bottom surface and a top surface, said foam resting with said bottom surface on said upper surface of said one or more spacers, said foam being disposed in such a way that it penetrates in between said one or more spacers and activates said pressure-responsive membrane switch in response to a force applied on said top surface that exceeds a certain threshold force; and a distance is disposed between said bottom surface and said pressure-responsive membrane when the seat is not-occupied, such that when the force is not applied on said top surface, then said bottom surface and the pressure-responsive membrane switch are not in contact, and the compressible foam does not penetrate in between said one or more spacers.