Steris Amsco 3085 SP, Maintenance Manual

Page: 78 / 228

3-4
764332-898
This condition results from air becoming entrapped in the
hydraulic system. Refer to
S
ECTION
7.28, H
YDRAULIC
S
YSTEM
A
IR
B
LEED
P
ROCEDURE
, for a procedure for
bleeding the air from the hydraulic system. If the bleed
procedure does not adequately reduce the seat/back
section variance, Table Control Software 56400-112
Revision 6 is available to correct the condition.
3.3.3 Table Articulation/Operation
3.3.3.1 Side Tilt
See Figure 3-2 and refer to Hydraulic System Schematic
(P134469-303) behind
R
EFERENCE
D
RAWINGS
Tab.
The side tilt articulations involve the use of one
mechanically-locking hydraulic cylinder, two lowering
brake check valves, one three-position directional valve
(S1 and S2) and one start/stop valve (S13 on early motor
and pump units).
Left side tilt is accomplished when solenoid S1 (and S13
on early motor and pump units) is energized. Fluid is
directed through the S1 valve to the lowering brake check
valve. At this point fluid is sent in two directions. One
direction allows for fluid to pass through a check valve
and straight to the cylinder. The second direction is
diverted off to act as a pilot for the return line restrictor.
Fluid from the cylinder is allowed to flow through the
return line check valve, the restriction orifice and S1 back
to the reservoir.
Right-side tilt is accomplished in the same manner as the
left side (outlined above), but uses solenoid S2 (and S13
on early motor and pump units) instead.
3.3.3.2 Column Raise/Lower
See Figure 3-3 and refer to Hydraulic System Schematic
(P134469-303) behind
R
EFERENCE
D
RAWINGS
Tab.
Raising and lowering of the tabletop involves the use of
one cylinder, one three-position directional valve (S5 and
S6), one lowering brake check valve and one start/stop
valve (S13, on early motor and pump units). A variable
orifice restrictor is added to the system at the inlet/outlet
of the raise/lower cylinder. This device is used to assist
speed control and to compensate for varying tabletop
loads.
The tabletop is raised when S5 (and S13 on early motor
and pump units) is energized. Fluid is directed to the
lowering brake check valve where it passes through the
valve and through the variable orifice restrictor to the lift
cylinder and causes the tabletop to rise.
The tabletop is lowered when S6 (and S13 on early motor
and pump units) is energized. Fluid is directed to the
lowering brake check valve to actuate the return line
restrictor, to control the lowering speed, and unseats the
pilot check valve. Fluid from the cylinder passes through
the variable orifice, back to S6 and on to the return port
of the reservoir.
Figure 3-2. Side Tilt
Figure 3-3. Column Raise/Lower
Directional Valves
(All Valves Shown Not
Actuated)
Electromagnet
Operator