Patent ID: 8714312
Filing Date: 2014-05-06
Classification: B66B

Abstract:
1. An elevator safety rescue system, comprising: at least one elevator guiderail; an elevator car disposed on the guiderail; a counterweight, a pulley system mounted above the guiderail, and a cable extending over the pulley system and connecting the counterweight to the elevator car, the counterweight having a greater weight than the elevator car and the cable so that the counterweight biases the elevator car to rise on the guiderail; at least one electrically powered drive motor disposed with the elevator car, the drive motor being coupled to an elevator transit mechanism, the drive motor having an output shaft; a positive displacement hydraulic pump rotationally coupled to the output shaft of the drive motor; a hydraulic circuit communicating with the hydraulic pump; an electro-hydraulic flow control valve disposed in the hydraulic circuit in series with the hydraulic pump; a restrictor orifice disposed in the hydraulic circuit in parallel with the electro-hydraulic flow control valve; and a normally operational electric circuit providing electric power to the electro-hydraulic flow control valve during normal elevator operation; wherein the electro-hydraulic flow control valve is maintained in an open condition when electrical power is provided thereto by the normally operational electric circuit, the electro-hydraulic flow control valve closing when electrical power thereto is terminated, thereby routing all hydraulic fluid through the restrictor orifice and restricting hydraulic flow through the hydraulic pump with corresponding reduction in rotational speed thereof and of the drive motor coupled thereto.