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:
Jun. 24, 1980
Filed:
Aug. 11, 1977
Robert G Miller, East Peoria, IL (US);
Michael L Render, Peoria, IL (US);
Caterpillar Tractor Co., Peoria, IL (US);
Abstract
A control for the automatic shifting of a multi-ratio power transmission. A memory is provided and programmed with the optimum vehicle speed shift points for upshift and downshift from each gear of the automatic range. The actual speed of the vehicle is periodically sampled, and each time it is, such speed is compared with the shift points for the gear which the transmission is in to see if a shift from such gear should be made. If it is determined from the speed sample that an upshift should be made, then the upshift speed points of higher gears are examined with reference to such speed sample to find the gear to which the transmission should be upshifted, i.e., the gear just above the highest gear having an upshift speed point which is less than the sampled speed. Having found such gear, the transmission is shifted thereto. Correspondingly, if it is determined from the speed sample that a downshift should be made (or can be made, in the event of a forced downshift condition), the downshift speed points of lower gears are examined with reference to such speed to find the gear to which a downshift should be made, i.e., the gear just below the lowest gear having a downshift speed point above the sampled speed. At any time, the operator may set any gear in the automatic range as the highest gear so that the transmission will not upshift beyond such gear.