Modern Means of Ensuring Safety During the Upward Movement of the Elevator Car and When it Stops in the Floor Area

Abstract

Elevators are potentially dangerous objects and, despite the fairly high safety of modern elevators, which is regulated by industrial safety rules, State Standards and manufacturer’s instructions, the requirements for elevators are constantly becoming more stringent. According to clause 5.6.1.1 (b) and clause 5.6.6 of GOST [All-Union State Standard] 33984.1–2016, it is required to prevent overspeeding when moving the cabin in both directions (up and down). To meet this requirement, elevators can be equipped with two single-acting speed limiters, one of which activates single-acting safety devices located on the car, and the second on the elevator counterweight. However, this solution leads to duplication of the safety system (in addition to two speed limiters and safety catches, two tensioners, two speed limiter ropes and a double number of limit switches are additionally required). This can only be justified in cases where there are used premises under the pit of the elevator shaft, for example an underground parking lot. This paper discusses elevator safety devices that meet the new requirements of modern domestic and foreign standards (EN 81–20:2014): double-acting safety devices and speed limiters, a system for preventing unintentional movement of the car (counterweight). Catchers and a speed limiter are interconnected devices that prevent the cabin (counterweight) from falling in the event of a break or when the supporting ropes are weakened, and also stop the cabin (counterweight) if the speed is unacceptable. However, as practice has shown, cases of uncontrolled upward movements of the elevator and while the elevator is parked with open doors are possible. This leads to accidents and injuries to passengers. The proposed designs of the limiter and catcher allow this to be avoided. Recommendations are proposed for modernizing old elevators, and, as a result, increasing their level of safety.