Steris Amsco 3085 SP, Maintenance Manual

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3-5
764332-898
3.3.3.3 Leg Up and Down
See Figure 3-4 and refer to Hydraulic System Schematic
(P134469-303) behind
R
EFERENCE
D
RAWINGS
Tab.
The leg up and down articulations require the use of two
hydraulic cylinders, two lowering brake check valves, one
three-position directional valve (S3 and S4) and one start/
stop valve (S13, on early pump and motor units).
Leg up is accomplished when solenoid S3 (and S13 on
early pump and motor units) is energized. Fluid is
directed through the S3 valve to the lowering brake check
valve. At this point fluid is directed two directions.
In one direction the fluid flows to the return line restrictor
and actuates it to control the speed of the articulation.
The second fluid direction unseats the holding check
valve and allows fluid to flow to both of the cylinders.
Return fluid from the cylinders comes back to the
lowering brake valve and passes through the now
activated restrictor port to the S3 valve and back to the
reservoir.
Leg down is accomplished when solenoid S4 (and S13 on
early pump and motor units) is energized. Fluid is
directed through the S4 valve to the lowering brake check
valve. Fluid is then directed in two directions. In one
direction the fluid actuates the return line restrictor to
control the articulation speed, and unseats the holding
check valve. The second direction allows fluid to pass
through an unrestricted port and on to the cylinders
causing them to retract. The return fluid from the
cylinders is directed back to the lowering brake check
valve. The fluid passes the unseated check valve to the
S4 valve and back to the reservoir.
3.3.3.4 Flex/Reflex
See Figure 3-5 and refer to Hydraulic System Schematic
(P134469-303) behind
R
EFERENCE
D
RAWINGS
Tab.
Flexing and Reflexing the tabletop requires the use of one
three-position directional valve (S-7 and S-8), two
lowering brake check valves, two position directional
valves (S-9S and S-10S), one start/stop valve (S-13, on
early motor and pump units), two back cylinders and one
seat cylinder.
The Flex articulation is accomplished by energizing the
S-8 solenoid valve, allowing fluid to flow through the
three-position directional valve. The fluid then flows to
one lowering brake check valve and passes through its
pilot check then on to the back cylinder two-position
directional valve (S-10S).
NOTE: S-9 and S-10 solenoids are not energized
during this articulation.
Figure 3-4. Leg Up and Down
Fluid passes through the two-position directional (S-10S)
valve and branches to the retract side of the back cylinders
and also to the second lowering brake check valve where
its pilot check is unseated and return line restrictor is
actuated. Fluid leaving the back section cylinders passes
through the two-position directional valve (S-10S) to the
retract side of the seat cylinder. Having piloted the check
valve, the fluid in the seat section is allowed to flow
through the two-position directional valve (S-9S), the
lowering brake check valve, the S-8 valve and back to the
reservoir.
The Reflex articulation is accomplished by energizing the
S-7 and S-13 (on early motor and pump units) solenoid
valves allowing fluid flow through the three-position
directional valve. The fluid then flows to one lowering
brake check valve and passes through its pilot check and
on to the seat cylinder two-position directional valve
(S-9S) and to the extend side of the seat cylinder.
Lowering Brake Check
Valve Module
Flow Fuse Valve Flow Fuse Valve
0.4 mm Cone