초록 ▼

A fluid pressure control circuit for a working vehicle having a transmission operable by a fluid pressure and a negative type fluid pressure parking brake. The control circuit comprises a fluid pressure cylinder movable to a first end position to place the transmission in a low speed position and to

A fluid pressure control circuit for a working vehicle having a transmission operable by a fluid pressure and a negative type fluid pressure parking brake. The control circuit comprises a fluid pressure cylinder movable to a first end position to place the transmission in a low speed position and to a second end position to place the transmission in a high speed position, a fluid supply line for supplying pressure fluid to the cylinder, and a control valve mounted on the fluid supply line. The control valve comprises a three position valve having a first position to release the pressure fluid from the parking brake and the fluid supply line, a second position to supply the pressure fluid to the parking brake and set the cylinder to the first end position, and a third position to supply the pressure fluid to the parking brake and set the cylinder to the second end position.

대표청구항 ▼

A fluid pressure control circuit for a working vehicle having transmission means operable by a fluid pressure, comprising: fluid pressure actuator means for controlling said transmission means said actuator means including a first cylinder acting to control a main change speed operation of said tran

A fluid pressure control circuit for a working vehicle having transmission means operable by a fluid pressure, comprising: fluid pressure actuator means for controlling said transmission means said actuator means including a first cylinder acting to control a main change speed operation of said transmission means and a second cylinder acting to control an auxiliary change speed operation of said transmission means, said second cylinder being movable to a first end position to place said transmission means in a low sped position and to a second end position to place said transmission means in a high speed position, a fluid supply line for supplying pressure fluid to said first and second cylinders of said fluid pressure actuator means, fluid pressure parking brake means connected to said fluid supply line, said fluid pressure parking brake means being a negative-type brake operable by fluid pressure to release parking brakes, and control valve means mounted on said fluid supply line and having a first position to release the pressure fluid from said fluid supply line and thereby from said fluid pressure parking brake means and a second position to supply the pressure fluid to said fluid pressure parking brake means, and to control the supply of the pressure fluid from said fluid supply line to said fluid pressure actuator means in order to set said second cylinder selectively to said first end position and said second end position.