Change speed control structure for hydraulic transmission
AssigneeKubota Corporation
InventorsSatoshi Machida, Shigekazu Hasegawa, Yoshimi Ota, Muneji Okamoto
Life of this patent
Estimating the term…
Abstract
A change speed control structure for a hydraulic transmission comprising a rotary valve for controlling a plurality of hydraulic actuators, a shift lever extending through a crooked guide groove, and a relay assembly for transmitting movements of the shift lever to the rotary valve on a reduced scale. The guide groove includes three straight portions extending parallel to one another in series and offset in a transverse direction thereof, each straight portion including a plurality of change speed positions. An adjacent pair of the straight portions are interconnected end to end by a bight portion.
Claims6
A change speed control structure for a hydraulic transmission having change speed hydraulic actuator means, comprising:
- a rotary valve for controlling said change speed hydraulic actuator means,
- shift lever means including a shift lever body and a guide groove for guiding the shift lever body,
- said guide groove including a first straight portion, a second straight portion and a third straight portion extending parallel to one another in series and offset in a transverse direction thereof, a first bight portion interconnecting an end of the first straight portion adjacent the second straight portion and an end of the second straight portion adjacent the first straight portion, a second bight portion interconnecting an end of the second straight portion adjacent the third straight portion and an end of the third straight portion adjacent the second straight portion, and an upper end, each of the straight portion including a plurality of serially increased change speed positions, and the speed positions of said second straight portion being serially higher than the speed positions of said first straight portion and the speed positions of said third straight portion being serially higher than the speed positions of said second straight portion, and
- a relay assembly for transmitting movements of said shift lever body to said rotary valve.
A change speed control structure for a hydraulic transmission having change speed control means, comprising;
- a rotary valve for controlling said change speed hydraulic actuator means,
- shift lever means including a shift lever body and a guide groove for guiding the shift lever body, said guide groove including a plurality of straight portions extending parallel to one another in series, offset in a transverse direction thereof and connected to one another at bight portions thereof, and
- a relay assembly for transmitting movements of said shift lever body to said rotary valve, characterized in that
- a first bight portion (W1) interconnects a connecting end of the first straight portion (L1) and a connecting end of the second straight portion (L2) and a second bight portion (W2) interconnects a connecting end of the second straight portion (L2) and a connecting end of the third straight portion (L3),
- that each straight portion (L1, L2, L3) includes a plurality of change speed portions, and
- that the first straight portion (L1) includes the change speed portion for a low speed forward drive, the second straight portion (L2) includes the change speed portion for an intermediate speed forward drive, and the third straight portion (L3) includes the change speed portion for a high speed forward drive.
Dependencies are inferred from the claim text.