Lit. No. 28270, Rev. 00
July 1, 2005
60
STRIKING AN OBJECT WHILE BACK DRAGGING – HYDRAULIC
QUILL
M
LEFT
RIGHT
3500 PSI
3500 PSI
4000 PSI
4000 PSI
1750 PSI
S6
S3
S1
S5
S4
S2
(C)
(D)
(A)
(B)
LIFT
FORCE APPLIED WHEN
BACK DRAGGING
FORCE APPLIED WHEN
BACK DRAGGING
RELIEF VALVE
SECONDARY
RELIEF VALVE
SECONDARY
SECONDARY BLOCK ASSY.
PRIMARY BLOCK ASSY.
VALVE
RELIEF
PRIMARY
PRIMARY
RELIEF
VALVE
VALVE
RELIEF
PUMP
P/O
CHECK
VALVE
P/O CHECK
VALVE
P/O
CHECK
VALVE
P/O
CHECK
VALVE
SV08-43
S3
ON
ON
ON
ON
SV08-2004
S1
ON
MOVEMENT
BLADE
RAISE
LOWER
SCOOP
VEE
SV08-30
S6
ON
ON
RIGHT
EXTEND
RIGHT
RETRACT
LEFT
RETRACT EXTEND
LEFT
S4
SV08-30
ON
ON
SV08-40
S2
ON
ON
ON
ON
SV08-40
S5
ON
ON
MOTOR
M
ON
ON
ON
ON
ON
ON
ON
ON
ON
ANGLE
RIGHT
ANGLE
LEFT
System Response
1. Hydraulic fluid is trapped in the
rod end of the right ram by P/O
check valve (B). Hydraulic fluid is
trapped in the rod end of the left
ram by P/O check valve (A).
The
hydraulic system does not
provide pressure relief while
back dragging.
