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:
Feb. 10, 1981
Filed:
Mar. 19, 1979
Michael M Palm, Marion, OH (US);
Dresser Industries, Inc., Dallas, TX (US);
Abstract
A drive system for crawler propelled earth working machinery is described. A first clutch which is movable between a drive position for transmitting drive from a drive source to a first drive sprocket and a lock position for locking the first drive sprocket to the frame is provided. A second clutch permits a second drive sprocket to free wheel. The second clutch has a drive position for transmitting drive from the drive source to the second drive sprocket and a lock position for locking the second drive sprocket to the frame. The first drive sprocket is, as well, lockable to the frame. The foregoing locking arrangements are selectively engageable with the first and second drive sprockets. Hydraulically actuatable shifting devices shift the first clutch between drive and lock positions and the second clutch between free wheel, drive and lock positions. A shifting preventing device releasable responsive to engagement of one of the drive sprocket locking devices prevents the second clutch from shifting to the free wheel position.