Abstract: A B-surface seat occupancy sensor unit (10) comprises a support plate (12) having a top surface (20) and a bottom surface, a plurality of spacer elements (14), which define an upper surface (18) of the unit. The top surface of the support plate is arranged recessed the upper surface. A first foam pad (22) is disposed between the spacer elements on the support plate. A recess (24) formed in the top surface of the support plate, underneath the first foam pad, accommodates a second foam pad (23) carrying a pressure-responsive membrane switch (26). The recess has a depth exceeding the total height of the pressure-responsive membrane switch and the second foam pad. The pressure-sensitive membrane switch projects laterally beyond opposite edges of the second foam pad.

Abstract: A pressure-responsive seat occupancy sensor unit (10) comprises a support plate (12) having a top surface (20) and a bottom surface, a plurality of spacer elements (14) defining an upper surface (18) of the pressure-responsive seat occupancy sensor unit, which upper surface the top surface of the support plate is arranged recessed from, a foam pad (22) disposed between the spacer elements on the support plate, a recess (24) formed in the top surface of the support plate, underneath the foam pad, and a pressure-responsive membrane switch (26) arranged in the recess. The recess has a depth exceeding the thickness of the pressure-responsive membrane switch. The foam pad is configured such that, upon it being compressed by application of pressure exceeding a certain threshold, it deforms so as to penetrate into the recess and activates the pressure-responsive membrane switch.

Abstract: A pressure-responsive seat occupancy sensor unit (10) for detecting an occupancy state of a seat comprises a support plate (12) with a support area (14), a pressure-responsive membrane switch (15), one or more spacers (16) arranged around the support area and a compressible foam. The membrane switch comprises a first carrier film and a second carrier film spaced from each other by a spacer film. The spacer film has therein an opening defining a cell. The membrane switch comprises at least two electrodes arranged in facing relationship with each other in the cell on the first and the second carrier film, respectively, in such a way that they are brought closer together, possibly into contact with each other, when sufficient pressure is applied on the membrane switch. The one or more spacers (16) protrude from the support, and define an upper surface (20) raised with respect to the support area. The compressible foam (18) rests with its bottom surface (22) on the upper surface of the one or more spacers.

Abstract: A seat (10) configured for detecting an occupancy state comprises an at least partially electrically conductive structural frame (14) comprising at least two fixation sites (22, 24) and an at least partially electrically conductive cushion-supporting spring (20) taut between the fixation sites. The cushion-supporting spring is electrically insulated from the structural frame. The seat comprises a cushion (16) supported by the cushion-supporting spring. The cushion-supporting spring and the structural frame are disposed in such a way that they are brought in electrical contact with each other when a force (34) is applied on the cushion that exceeds a predefined threshold force.

Abstract: A pressure-responsive seat occupancy sensor unit (10) comprises a support plate (12) having a top surface (20) and a bottom surface, a plurality of spacer elements (14) defining an upper surface (18) of the pressure-responsive seat occupancy sensor unit, which upper surface the top surface of the support plate is arranged recessed from, a foam pad (22) disposed between the spacer elements on the support plate, a recess (24) formed in the top surface of the support plate, underneath the foam pad, and a pressure-responsive membrane switch (26) arranged in the recess. The recess has a depth exceeding the thickness of the pressure-responsive membrane switch. The foam pad is configured such that, upon it being compressed by application of pressure exceeding a certain threshold, it deforms so as to penetrate into the recess and activates the pressure-responsive membrane switch.

Abstract: A B-surface seat occupancy sensor unit (10) comprises a support plate (12) having a top surface (20) and a bottom surface, a plurality of spacer elements (14), which define an upper surface (18) of the unit. The top surface of the support plate is ar ranged recessed the upper surface. A first foam pad (22) is disposed between the spacer elements on the support plate. A recess (24) formed in the top surface of the support plate, underneath the first foam pad, accommodates a second foam pad (23) carrying a pressure-responsive membrane switch (26). The recess has a depth exceeding the total height of the pressure-responsive membrane switch and the second foam pad. The pressure-sensitive membrane switch projects laterally beyond opposite edges of the second foam pad.

Abstract: A pressure-responsive seat occupancy sensor unit (10) for detecting an occupancy state of a seat comprises a support plate (12) with a support area (14), a pressure-responsive membrane switch (15), one or more spacers (16) arranged around the support area and a compressible foam. The membrane switch comprises a first carrier film and a second carrier film spaced from each other by a spacer film The spacer film has therein an opening defining a cell. The membrane switch comprises at least two electrodes arranged in facing relationship with each other in the cell on the first and the second carrier film, respectively, in such a way that they are brought closer together, possibly into contact with each other, when sufficient pressure is applied on the membrane switch. The one or more spacers (16) protrude from the support, and define an upper surface (20) raised with respect to the support area. The compressible foam (18) rests with its bottom surface (22) on the upper surface of the one or more spacers.

Abstract: A seat (10) configured for detecting an occupancy state comprises an at least partially electrically conductive structural frame (14) comprising at least two fixation sites (22, 24) and an at least partially electrically conductive cushion-supporting spring (20) taut between the fixation sites. The cushion-supporting spring is electrically insulated from the structural frame. The seat comprises a cushion (16) supported by the cushion-supporting spring. The cushion-supporting spring and the structural frame are disposed in such a way that they are brought in electrical contact with each other when a force (34) is applied on the cushion that exceeds a predefined threshold force.

Abstract: An occupancy sensor assembly with a variable-resistance seat occupancy sensor comprises an adapter circuit for connecting the occupancy sensor to a control unit. The adapter circuit includes switching means for switching, between discrete states and as a function of resistance of the seat occupancy sensor, a current drawn from the control unit by the assembly.