SEAL-LIP TYPE 1334295 - Caterpillar

Illustration 1 g00689160
Sequence and Pressure Control Valve (Apron) (1) Passage for head end of cylinder (2) Shims (3) Relief valve (4) Stem (5) Passage (6) Check valve (7) Piston (8) Opening to common oil line (9) Passage for rod end of cylinderApron HOLD PositionThe sequence and pressure control valve (apron) allows the oil to flow from the rod end to the head end of the apron cylinder when an external force lifts the apron. When an external force acts on the apron and the apron valve stem is in the HOLD position, there is an increase in oil pressure in the rod end of the apron cylinder. When the oil pressure in the rod end of the apron cylinder increases to a set pressure, the pressure oil in the rod end of the apron cylinder and in passage (9) opens relief valve (3). The pressure oil from the rod end of the apron cylinder will flow from passage (9) through open relief valve (3) into passage (1) to the head end of the apron cylinder.
Illustration 2 g00689174
Sequence and Pressure Control Valve (Apron) (10) Common oil line to opening (8) (11) Line from control valve to passage (1) (12) Line from rod end of cylinder to passage (9) (13) Line from head end of cylinder to passage (1) Apron RAISE PositionThe pressure oil from the pump flows through passage (1) to the head end of the apron cylinder. The pump oil in passage (1) also moves piston (7) which opens check valve (6). As the apron moves up, the oil from the rod end of the cylinder flows through open check valve (6) into opening (8) and through common oil line (10) to the main control valve.Apron LOWER PositionWhen the apron is lowered, the pressure oil from common oil line (10) will flow through opening (8). The pressure oil will then open check valve (6) and flow through passage (9) into the rod end of the apron cylinder. The pressure oil that flows through opening (8) also flows through passage (5) to stem (4). The pump oil moves the stem against relief valve (3) in order to keep the relief valve closed. The oil from the head end of the apron cylinder flows through passage (1) to the main control valve.Apron FLOAT PositionWhen the apron valve stem is in FLOAT position, the weight of the apron causes oil from the head end of the apron cylinder to flow through line (13) into passage (1). The oil from the head end of the apron cylinder moves piston (7) to the right. When piston (7) moves to the right, check valve (6) opens. This allows oil from the rod end of the apron cylinder to flow through line (12) into passage (9). The oil flows through opening (8) into common oil line (10) back to the main control valve. If an external force moves the apron upward, pump oil from line (11) flows into the head end of the apron cylinder. As the