SHAFT-COUPLING 1G7437 - Caterpillar

Illustration 1 g00672250
(1) Pilot control valve (stick and swing) (2) Pilot control valve (boom and bucket)
Illustration 2 g00637954
(3) Joystick control (4) Plate (5) Rod (6) Spring (7) Seat (8) Spring (9) Spring (10) Return chamber (11) Return passage (12) Passage (13) Spool (14) Port (15) Rod (16) Seat (17) Spring (18) Spring (19) Return passage (20) Passage (21) Spool (22) PortWhen joystick control (3) is moved to the left, plate (4) tilts to the left. Plate (4) pushes downward on rod (5) and on seat (7). Seat (7) pushes against the force of spring (9) and the force of spring (8). The force of spring (9) shifts spool (13) downward, and passage (12) opens. The oil can now go through passage (12) and out port (14) to the implement and travel control valve. The oil pressure shifts the stem of the implement and travel control valve. This enables the implement operation or the swing operation.The oil at the opposite end of the stem flows back through port (22), through return passage (19), and into return chamber (10). The oil then flows back to the tank.When rod (5) is not forced down, return passage (11) is open and passage (12) is blocked.When joystick control (3) is moved to the right, plate (4) tilts to the right. Plate (4) pushes downward on rod (15) and on seat (16). Seat (16) pushes against the force of spring (18) and the force of spring (17). The force of spring (18) shifts spool (21) downward, and passage (19) opens. The oil can now go through passage (20) and out port (22) to the implement and travel control valve. The oil pressure shifts the stem of the implement and travel control valve. This enables the implement operation or the swing operation.The oil at the opposite end of the stem flows back through port (14), through return passage (11), and into return chamber (10). The oil then flows back to the tank.When rod (15) is not forced down, return passage (19) is open and passage (20) is blocked.When joystick control (3) is released, the control levers are returned to the NEUTRAL position by spring (8) and spring (17) .The pilot oil that is sent to the implement and travel control valve changes proportionally to the travel distance of joystick control (3). Movement of the stem of the implement and travel control valve causes a change in oil flow to the cylinders and/or motors. The change in oil flow will be proportional to the change in pilot oil pressure. Fine movement of the control lever allows fine control of operation of the cylinders and/or motors.When joystick control (3) is moved slightly to the left, only spring (9) controls spool (13). When joystick control (3) is moved slightly to the right, only spring (18) controls spool (21). A small lever movement results in a small pressure change and fine control.A large movement of joystick control (3) to the left will cause rod (5) and seat (7) to