US Patent 8939262 Elevator over-acceleration and over-speed protection system

An elevator system includes an electronic system capable of triggering a machine room brake and an electromagnetic safety trigger with low hysteresis and with minimal power requirements that can be released to engage safeties, when car over-speed and/or over-acceleration is detected. The electromagnetic trigger may be reset automatically and may be released to engage the safeties, during the reset procedure. The system includes a processing system that is configured to decrease response time and to reduce the occurrence of false triggers caused by conditions unrelated to passenger safety, such as passengers jumping inside the elevator car.