Digital fluid power as enabler for soft catching safety gears

The present paper describes the principal safety architecture of state-of-the-art passenger elevators and their restrictions, especially for new elevator technologies. From this, the obvious need for a controllable brake, instead a safety gear, to avoid normative accidents can be derived. The solution presented demonstrates the advantages of digital hydraulic solutions, especially when they are developed in a highly integrated way with the overall system. LCM designed a fully integrated electro-hydraulically controlled, spring-loaded safety brake for the special needs in roped and also rope less elevators. The high demands in cabin deceleration combined with a low power consumption can only be realized with a digital hydraulic approach. Additionally, different safety-related situation and several additional comfort functions have to be realized. This entire system is referred to as the so-called Intelligent Safety Brake – ISB. This paper describes the basic braking functions of the ISB as well as its additional functions such as safety and comfort and the corresponding final hydraulic circuit. Strategies to operate the system in different situations, its needed components and the integration concept are discussed. Finally, the results of extensive tests in free falling test facilities and operational tests in test elevators with the ISB are presented. The ISB defines the next level of elevator safety brakes and is an important enabler for new elevator technologies like ropeless, three-dimensional moving multi-cabin systems [1] [2]. Thereby the ISB is another good example of Digital Fluid Power as an enabler for novel future technologies and applications.