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:
Aug. 02, 1994
Filed:
Dec. 17, 1992
Garth H Bulgrien, Ephrata, PA (US);
Ford New Holland, Inc., New Holland, PA (US);
Abstract
In a powershift transmission having electro-hydraulic clutches for selectively connecting an input shaft in driving relationship with an output at any one of a plurality of output to input shaft speed ratios, creeper gear speeds, less than those obtained by selecting the lowest output to input shaft speed ratio, are obtained by placing the transmission in the lowest gear (forward or reverse) and controlling the output shaft speed by automatically controlling clutch slippage. Any one of a plurality of forward or reverse creeper gear speeds may be selected by operation of a gearshift lever. The speeds of the input and output shafts are sensed and a microprocessor responds to the sensed shaft speeds and the selected creeper gear speed to control slipping of the clutch. In one embodiment the output shaft speed is controlled to a specific speed value independent of the input shaft speed. In a second embodiment, the output shaft speed is controlled to obtain a specific ratio of output to input shaft speed.