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. 29, 1997
Filed:
Jun. 06, 1995
Alan R Coutant, Chillicothe, IL (US);
Jerry D Marr, Metamora, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
A method is disclosed for controlling the shift points in a continuously variable transmission having a closed loop control wherein the output of the continuously variable transmission is generated by a hydrostatic transmission or by a combination of the hydrostatic transmission and a mechanical transmission having a summing planetary and high and low speed clutches. The method comprises the steps of sensing the input and output speeds of the continuously variable transmission and the speed of the output from the hydrostatic transmission to monitor the speed ratios therein, comparing an operative transmission speed ratio of the transmissions to a predefined established transmission speed ratio, disengaging the high or low speed clutch once the predefined established transmission speed ratio is reached, increasing or decreasing the speed of the output of the hydrostatic transmission following disengagement of the high or low speed clutch, and engaging the other of the high or low speed clutch once the change in output speed of the hydrostatic transmission has substantially synchronized the speeds relative to the high or low speed clutches so that the output torque and speed of the transmission before and after the shift is substantially equal.