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:
May. 25, 1993
Filed:
May. 16, 1991
Richard N Fargo, Plainville, CT (US);
Bennie J Murah, Amherst, MA (US);
Otis Elevator Company, Farmington, CT (US);
Abstract
According to the invention, a valve for use with a variable speed motor and pump in an hydraulic elevator balances a fluid pressure force on a pump side of a control valve with a fluid pressure force on a cylinder side of the control valve before an elevator cab moves either upwardly or downwardly. On the pump side of the valve, a separate circuit, which is controlled by a solenoid, directs the pump fluid pressure force behind the valve until the sum of the fluid pressure acting on the pump side of the control valve overcomes the fluid pressure on the cylinder side of the control valve to open the valve.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile