PISTON 1039678 - Caterpillar

Components
Illustration 1 g03729973
Quick coupler components
(1) Port - UNLOCK
(2) Port - LOCK
(3) Quick coupler hydraulic cylinder
(4) Check valve
(5) Wedge
Illustration 2 g03779459
Switch panel
(6) Quick coupler electrical switch
Quick coupler hydraulic cylinder (3) is a double acting hydraulic cylinder. The cylinder rod is extended to LOCK the coupler by extending wedge (5). The cylinder rod is retracted to UNLOCK the coupler by retracting wedge (5). A solenoid valve is used to control cylinder (3).
Check valve (4) is used to hold cylinder (3) in the LOCKED position when oil pressure is not supplied to the head end of cylinder (3).
Quick coupler electrical switch (6) is the operator input that is used to control the flow of oil to coupler cylinder (3). Switch (6) is either in the LOCKED or UNLOCKED position.Coupler Lock
Illustration 3 g03779067
Illustration 4 g03778872
Hydraulic schematic - LOCK
(1) Port - UNLOCK
(2) Port - LOCK
(3) Quick coupler hydraulic cylinder
(4) Check valve
(6) Quick coupler control switch
(7) Quick coupler
(8) Quick coupler control valve
(9) Solenoid valve
(10) Hydraulic oil tank
(11) Pump
(12) Bucket control lever
(13) Bucket hydraulic cylinder When quick coupler electrical switch (6) is in the LOCK position, the machine ECM does not send an electrical signal to solenoid valve (9). Solenoid valve (9) is de-energized.When solenoid valve (9) is de-energized, oil from pump (11) is directed to quick coupler control valve (8). Main pump oil flows through the check valve in quick coupler control valve (8) to the head