TM 5-3805-260-24
the head end of the door cylinder goes through the line to
opening (15), through check valve (19) and out the line
from opening (18) to the control valve (tank).
SCRAPER CONTROL VALVE
1. Relief valve. 2. Opening (to bowl cylinders). 3. Inlet
(pump). 4. Opening (to bowl cylinders). 5. Hole. 6.
Bowl valve spool. 7. Hole. 8. Passage (from carry
check valves). 9. Hole. 10. Opening (for rod end of
ejector and head end of door cylinder). 11. Outlet (to
tank). 12. Opening (for head end of ejector and rod
end of door cylinder). 13. Ejector valve spool. 14.
Ejector kickout valve. A. UP position. B. HOLD
position. C. DOWN position. D. EJECT (open)
position. E. HOLD position. F. RETURN (close)
position.
DOOR CHECK VALVE
15. Opening (for head end of door cylinder). 16. Seat.
17. Opening (from rod end of door cylinder and head
end of ejector cylinder). 18. Opening (to control
valve and rod end of ejector cylinder). 19. Check
valve.
When ejector valve spool (13) is in RETURN position
(F), detent balls in ejector kickout valve (14) keep the
valve spool and the control lever in the RETURN
position. The pump oil in the control valve goes out
through opening (10) to the rod end o, the ejector
cylinder and through the door check valve to the head
end of the door cylinder.
DOOR CHECK VALVE
15. Opening (for head end of door cylinder). 17. Oil
line from rod end of door cylinder and head end of
ejector cylinder. 18. Opening (for oil line to control
valve and rod end of ejector cylinder).
The pump oil through the line to opening (I 8), in the
door check valve, goes through the passage in check
valve (19), pushes seat (16) open and then goes through
opening (15) and the line to the head end of the door
cylinder. The pump oil in the head end of the door
cylinder moves the piston and rod, connected to the
door, to close the door. The pump oil in the rod end of
the ejector cylinder now moves the piston and rod,
connected to the ejector, to move the ejector to the rear
of the scraper. When the piston can not move the ejector
any farther, because it is against a stop, the pressure of
the pump oil increases.
EJECTOR KICKOUT VALVE
20. Orifice (in valve spool). 21. Poppet valve. 22.
Piston. 23. Spring (for valve spool). 24. Plunger. 25.
Detent ball (three). 26. Detent (in housing). E. HOLD
position of valve spool. F. RETURN position of valve
spool.
The pump oil is also in a passage, in ejector valve
spool (13), through orifice (20) against poppet valve (21)
when the valve spool is in RETURN position (F). When
the pressure of the pump oil in the rod end of the ejector
cylinder, the head end of the door cylinder and through
orifice
(20)
in
valve
spool
(13)
increases
to
4-23
