LEVER 8X9325 - Caterpillar

Illustration 1 g00533808
(1) Pilot valve for the bowl (2) Pilot valve for the ejector (3) Pilot valve for the elevator (4) Inlet port for the pilot oil
Illustration 2 g00430301
(5) Pressure reducing valveWhen the engine is running, pilot oil flows from the cushion-hitch pump to pressure reducing valve (5) . Then, the oil flows from pressure reducing valve (5) to the pilot valve. Pilot valve (1) and pilot valve (2) are controlled manually by the operator. The pilot valves send pressurized oil from the pilot system to the spools of the main control valve. Also, pilot valve (3) is controlled manually by the operator. Pilot valve (3) sends pressurized oil from the pilot system to the elevator pump and the blocker valve. The spools in the main control valve control the operation of the bowl cylinders, floor cylinder and ejector cylinder. The elevator pump and the elevator motor control the elevator. There are two plunger capsule assemblies in each pilot valve.The supply oil for the pilot valve is taken from the circuit of the cushion-hitch. This circuit is at a standby pressure of 16000 kPa (2320 psi). This oil flows into inlet port (4) . There is an orifice in this passage that will provide stability for the pilot valve. Also, there is a screen in this line. This screen protects the orifice in the passage from being plugged by contamination.When a pilot valve lever is moved, one plunger assembly is pushed down into the pilot valve. The plunger assembly causes the metering and plunger capsule assemblies to move down. As the metering capsule assembly is pushed down, the pressure in the work port increases. As the pressure in the work port increases, the spool in the main control valve shifts. This controls the speed of the cylinder.When the pressure increases in the work port of the elevator circuit, the stem in the blocker valve is fully shifted. This will upstroke the elevator pump. A signal may also be sent to the directional control valve in order to shift to reverse.