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:
Sep. 08, 1998
Filed:
Mar. 03, 1997
Randy R Hayward, Mapleton, IL (US);
James E Winzeler, East Peoria, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
A transmission warm-up control strategy is provided for an automatic transmission used in a machine that is started or operated in cold conditions. When the operating value of the oil in the transmission is below a predetermined level, as sensed by a temperature sensor or a viscosity sensor, a controller turns on an indicator lamp, de-energizes all of the solenoid to the solenoid actuated valves, and holds for a predetermined period of time. The respective solenoids are incrementally energized and held for a second period of time while continuously monitoring the operating condition of the oil in the transmission. Once the operating condition of the oil is above the predetermined operating value, the indicator lamp is turned off and the system is returned to normal operating conditions. If the shift lever is moved from the park position during warm-up, all solenoids are de-energized and the indicator lamp is set to flash. The condition is held for the first predetermined period of time then the solenoids for the neutral clutches are energized and if the shift lever is not in the neutral position, the controller require that the shift lever be returned to the neutral or park position.