Patent ID: 6742629
Filing Date: 2004-06-01
Classification: B66B,F15B

Abstract:
Control valve unit (28) for an hydraulic elevator, comprising control valves (5, 15) and pilot valves (5v, 15v) for controlling the flow of hydraulic oil from a tank (11) to a lifting cylinder (3) driving an elevator cabin (1) and/or from said lifting cylinder (3) to said tank (11), wherein for an upward movement of said elevator cabin (1) said hydraulic oil can be conveyed by means of a pump (10) driven by an electromotor (12) from said tank (11) through a control valve unit (28) to said lifting cylinder (3) and for a downward movement of said elevator cabin (1) said hydraulic oil can be conveyed through said control valve unit (28) to said tank (11), wherein for controlling said downward movement of said elevator cabin (1) one single pilotable control valve (5) is provided to act as a check valve as well as a proportional valve and for controlling said upward movement of said elevator cabin (1) one single pilotable control valve (15) is provided to act as a check valve as well as a proportional valve,characterized in that in said control valve (15) controlling the downward movement force transmission from said pilot valve (5v) thereof is effected by means of a piston (48) acting against a main valve regulating spring (49) via a control rod (50) to an opposed piston (38) which via a check rod (39) fixed thereto moves a flow restrictor (35), and in said control valve (15) controlling the upward movement force transmission from said pilot valve (15v) thereof is effected by means of a piston (68) acting against a main valve regulating spring (69) via a control rod (70) to a flow restrictor (55) and said flow restrictor (55) is solidly connected to an opposed piston (58) via a check rod (59).