Safety circuit for servo-driven vehicle side-window - has conducting strips on window edge and on door frame with test circuit to detect obstructions

摘要

The closing edge (N) of the window and the corresp. window frame (D,L) are fitted with conducting strips. The test circuit (P) provides a pulsed test signal and measures the resistance between the window edge and the seals to detect any obstruction. The test signals are of a level safe for contact. The test circuit stops the window closing drive and reverses the drive. A safety interlock has an emergency control which overrides the safety circuit to enable the driver to close the window in an emergency e.g. to prevent a thief reaching into the vehicle. The system is also used to detect the window closed position and to switch off the servo drive. ADVANTAGE - Simple protection, no complex contact switches required.