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:
Dec. 10, 1985
Filed:
Aug. 20, 1984
Richard W Reynolds, Rockford, IL (US);
Sundstrand Corporation, Rockford, IL (US);
Abstract
A hydraulic differential transmission utilizing an input differential and having a hydrostatic transmission with a variable output speed to the input differential whereby the speed of the transmission drive output can be maintained constant with variable drive input speeds to the transmission. The hydraulic differential transmission has a pair of parallel drive trains between the drive shaft of the fixed displacement unit of the hydrostatic transmission and the input differential, with the two drive trains providing different drive ratios therebetween. A first drive train including an overrunning clutch provides a one to one drive ratio therebetween when operating at higher drive input speeds. The other drive train includes a second differential and a second overriding clutch providing a lesser drive ratio between the fixed displacement hydraulic unit and the first differential when operating at lower drive input speeds. The overrunning clutches enable a shift between drive trains at a shift point where the drive shaft of the fixed displacement hydaulic unit changes direction of rotation without any discontinuity in the drive at the shift point. The change in drive ratios for operation at the higher drive input speeds causes the hydraulic units of the hydrostatic transmission to operate at higher pressures and nearer their normal pressure capabilities.