Hyster F007 - Extend and Retract Circuit; Twist Lock Circuit and Control; Model 553 - Horizontally Mounted

Operation 5000 SRM 969
1. NUT
2. WASHER
3. STUB S
HAFT
4. HOOK
5. SPRING
6. END BEAM
7. PLATE
,BOLT
Figure 3. End Beam Assembly (Model 555)
EXTEND AND RETRACT CIRCUIT
The attachments are designed to lift either 20- or
40-ft containers. The optional 30-ft stop kit allows
lifting 30-ft containers. The 30-ft position is obtained
by energizing the 30-ft stop while extending or re-
tracting the beams.
When the operator selects the extend or retract func-
tion with the control lever, the appropriate solenoid is
energized and oil from the main control valve is sup-
plied to the extension cylinders via the control valves.
A relief valve within the circuit limits hydraulic pres-
suretoamaximum14.0MPa(2030psi)toprotectthe
extension cylinders from damage.
TWIST LOCK CIRCUIT AND CONTROL
For model 553, locking of the twist locks is done man-
ually only. For model 558, locking of the twist locks
can be either manually or automatically. Unlocking
is always done manually. Locking or unlocking is
controlled by energizing the relevant solenoids and
spools. Relief valves within the circuit limit the max-
imum hydraulic pressure to 8 MPa (1160 psi).
Model 553 - Horizontally Mounted
The horizontally-mounted twist lock circuit uses a
twist lock motor and three sensors. See Figure 2. The
three sensors register if the twist lock is locked, twist
lock is unlocked, and container is seated.
To pick up a container, twist locks must be in un-
locked position. The horizontal twist locks enter
side pockets of container corner castings. When
completely entered, the seated sensor registers and
switches related amber light ON. When both seated
sensors register and both amber lights are ON, twist
lock circuit will allow twist lock motor to be operated.
For model 553, locking and unlocking of twist locks
is done manually only. Opening twist locks is also a
manual operation.
To protect against possibility of twist locks opening
unintentionally, twist locks have a flat surface, which
touches vertical area of the corner casting when con-
tainer is being carried. The weight of container locks
the flat surface of twist lock against vertical area of
corner casting and prevents twist lock from turning.
It therefore is important to make sure that the at-
tachment is completely seated before locking or un-
locking twist locks.
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