Samson 3767 Mounting And Operating Instructions - Lever
The rotary motion of these actuators is con-
verted into a linear motion required by the
pneumatic control unit of the positioner us-
ing the cam disk of the actuator shaft and a
cam follower roll on the positioner lever.
Note:
Use Table 7 to check whether the
proper range spring (1 or 2) has been in-
stalled. Range spring 1 is installed as stan-
dard. If necessary, replace it with range
spring 2 included in the accessories and at-
tach it at the outer slot.
Double-acting springless rotary actuators re-
quire the use of a reversing amplifier on the
connection side of the positioner housing
(see section 2.3.4).
When using a reversing amplifier, the pres-
sure regulator (9, Fig. 2) must be turned
clockwise as far as it will go (also see sec-
tion 3.1.2).
When attaching the positioner to the
SAMSON Type 3278 Rotary Actuator (Fig.
8, left), the actuator's inside and the unused
reverse side of the diaphragm are filled with
the positioner's exhaust air. Additional pip-
ing is not required. When attaching the
positioner to actuators from other manufac-
turers (Fig. 8, right), the reverse side of the
diaphragm can be filled with air over a pipe
connection installed between the actuator
and the intermediate piece.
2.3.1 Mounting the cam follower
lever
1. Place the lever with the cam follower roll
(35) on the side of the feedback lever
(37) opposite the insert nuts. Fasten with
the supplied screws (38) and washers.
Note:
To ensure a close physical contact be-
tween the cam follower roll and the cam
disk, fix the spring contained in the accesso-
ries kit (order no. 1400-6660) at the rear of
the positioner housing (see Fig. 5).
2.3.2 Mounting the intermediate
piece
SAMSON Type 3278 Actuator
1. Screw the adapter (36) to the free end of
the actuator shaft.
2. Attach the intermediate piece (34) to the
actuator housing using two screws. Align
the intermediate piece to ensure that the
air connections of the positioner point to-
wards the diaphragm housing.
3. Align the cam disk (40) and scale (39)
as described in section 2.3.3 and fasten
with screws.
Actuators according to VDI/VDE 3845
(fixing level 1)
1. Place the complete intermediate piece
(34, 44, 45, and 42) onto the mounting
bracket that came with the actuator and
fasten with screws.
2. Align the cam disk (40) and scale (39)
as described in section 2.3.3 and fasten
with screws.
20
EB 8355-2 EN
Attachment to control valve