The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 17, 2001
Filed:
Dec. 24, 1998
James W. Fuller, Amston, CT (US);
Randall K. Roberts, Amston, CT (US);
United Technologies Corporation, Hartford, CT (US);
Abstract
A system is provided for the semi-active damping of oscillations during vertical motion of an elevator car relative to a desired trajectory along a relatively lengthy elevator travel path. The elevator car is connected to a motor-controlled support rope in a manner allowing limited relative vertical motion therebetween. A soft spring and a controllable damping means are connected in parallel between the rope and the elevator car. The damping means may be a hydraulic piston and cylinder arrangement controlled via a variable orifice valve. The spring may be a gas-pressurized accumulator connected to the hydraulics of the damping means. A control system provides a motion command signal to control the motor for motion control and the variable orifice valve for damping oscillations. Full closure of the variable orifice valve effectively locks the damping means to maintain a position when the elevator car is braked, and a tension release control gradually releases any accumulated tension across the valve when the brake is released.