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:
Nov. 22, 1988
Filed:
Jun. 19, 1987
Denis D Shah, Union, NJ (US);
Richard L Thomas, Slocum Township, Luzerne County, PA (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
A hydraulic elevator system for monitoring a cold oil thermostat mounted on a hydraulic oil reservoir to prewarm the oil prior to passenger service by recirculating the oil in the reservoir through a pumping path which goes past up and down valves, thus bypassing the hydraulic jack. A control circuit including a microprocessor generally controls all car and corridor functions and is photo-coupled to the thermostat for an input signal which interacts with a program module in a random access memory which is run in sequence by the microprocessor. The program module provides a minimum timer phase for pump motor energization which is short but normally adequate to circulate the oil to standard minimum operating temperature before the sequencing activates a maximum timer phase which is cumulative in time for continuous bypassing until shutdown. The tiered total timer counting thus prevents overtemperature problems to avoid damage to the pump motor windings if the thermostat fails and also prevents recycling.