CYLINDER AS 2039828 - Caterpillar

Illustration 2 g03726634
Screed Mounted Controls (21) Left screed operator station (22) Horn switch (23) E-stop switch (24) Left auger switch (25) Left conveyor switch (26) Right material height switch (27) Left material height switch (28) Right screed operator station (29) Horn switch (30) E-stop switch (31) Right auger switch (32) Right conveyor switch (33) Left material height switch (34) Right material height switchNote: All tractor circuitry descriptions are of the AP300D Asphalt Paver.The screed mounted controls are switches and dials that control systems on the tractor. All of the screed mounted controls are located on the two operator stations on the screed.Note: For additional information, refer to the tractor documentation.Hydraulic Schematics
Illustration 3 g03726647
Screed Extender in Hold (1) Left extender cylinder (2) Right extender cylinder (3) Left extender valve group (4) Oil distribution manifold (5) To drain line on tractor (6) Cylinder pressure line from tractor (7) Extender manifold (8) Right extender valve groupThe screed uses one double-acting cylinder to move each extender. The cylinders are each controlled by a valve assembly with two solenoids. One solenoid extends the cylinder and one solenoid retracts the cylinder. The solenoids are controlled by the extender control circuits. The solenoids enable hydraulic flow to extend or retract the extender.When none of the solenoids are energized, the valve remains in the hold position. In this case, both sides of the cylinder are blocked by the pilot-opened check valves, and the cylinder is locked in position. Fluid flow from port "7" of oil distribution manifold (4) flows through the extender valve groups and into the return line. The return line of the extender manifold is connected to port "6" of the oil distribution manifold.
Illustration 4 g03726664
Screed Extender with Left Cylinder Extend and Right Cylinder Retract (1) Left extender cylinder (2) Right extender cylinder (3) Left extender valve group (4) Oil distribution manifold (5) To drain line on tractor (6) Cylinder pressure line from tractor (7) Extender manifold (8) Right extender valve groupWhen a left screed extend switch is in the EXTEND position, current is directed to the extend solenoid. The solenoid opens a passage to the rod end of left extender cylinder (1). Pressure in the pilot line opens the check valve in the return line.Left extender cylinder (1) extends until the cylinder is fully extended or the switch is released. As the cylinder extends,