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. 07, 2015
Filed:
Apr. 28, 2010
Sebastiano Acquaviva, Pino Torinese, IT;
Sebastiano Acquaviva, Pino Torinese, IT;
Brea Impianti S.U.R.L., Martina Franca, IT;
Abstract
A control system for a hydraulic elevator. The system () controls an elevator () which includes an elevator cylinder () with a piston () coupled to a car (), a pump () having an outlet coupled to the elevator cylinder (), and an electric motor () coupled to the pump (). A speed regulator () for controlling the speed of the car () is driven in predetermined modes, such that the pump () rotates at predefined speed. The speed regulator () is driven such that the motor () of the pump () is supplied with a voltage having a frequency (f) the value of which corresponds to a predefined speed value (ω), increased by an amount (cf; f, f) which is a predetermined function of the working pressure (P) of the pump (). This balances the effect of the leakage of operating hydraulic fluid in the pump ().