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. 14, 1992
Filed:
Jun. 18, 1991
Takayuki Sato, Kanagawa, JP;
Mikio Kawaguchi, Kanagawa, JP;
Kabushiki Kaisha Komatsu Seisakusho, Tokyo, JP;
Abstract
A method of controlling a speed changing operation wherein the method is preferably employable for a caterpillar drive type construction machine including a direct transmission is disclosed. When a shift-up speed changing operation is to be performed, the method is practiced by way of the steps, i.e., a step of releasing leftward and rightward steering clutches from the operatively engaged state thereof, a step of increasing an engine speed, a step of releasing a main clutch from the operatively engaged state thereof, a step of releasing the dog clutch which has selected the present speed stage from the meshing engagement thereof, a step of bringing the main clutch in the operatively engaged state, a step of detecting the rotational speed of an output shaft in the transmission, a step of setting a target engine speed for realizing synchronous meshing engagement of a dog clutch for a next speed stage based on the rotational speed of the output shaft and the number of gear teeth to be brought in meshing engagement in the transmission when it is assumed that the next speed stage has been selected, a step of rotating the engine at the target engine speed, a step of bringing the dog clutch for the next speed stage in the operatively engaged state thereof, a step of bringing the leftward and rightward steering clutches in the operatively engaged state, and a step of rotating the engine at the engine speed which has been designates by actuating a throttle lever. With such construction, the method of the present invention assures that the shift-up speed changing operation can smoothly be performed without any necessity for interrupting movement of the caterpillar drive type construction machine.