Obstruction-responsive apparatus

摘要

Apparatus responsive to an obstruction in the window opening of a power-driven window in a motor vehicle comprises two electrically conductive strips (60,62) embedded in and running along a flexible window channel in the top of the frame of the window opening. The conductive strips (60,62) are normally held spaced apart. A small electrical current flows through the conductive strips (60,62) via high value resistors (87,91). One of these resistors (91) interconnects one of the ends of one of the conductive strips (60) to the corresponding end of the other strip (62). A control unit (88) monitors the electrical potential difference across the other ends of the strips (60,62). An obstruction carried upwardly in the window opening by the closing window will move the conductive strips (60,62) into contact with each other, and will be detected by the fall in potential difference across the ends of the strips (60,62) connected to the control unit (88). Any electrical discontinuity in the strips (60,62) will interrupt the small current flowing through them, and this also will be detected by the control unit (88). The resistor (91) is formed by treated elastomeric material and can be placed in electrical contact with and between the ends of the strips (60,62) such as by an injection process or by adhesive, eliminating the need for an inefficient soldering or similar operation.