Attachment To Rotary Actuators; Mounting The Cam Follower Roll Lever; Mounting The Intermediate Piece - Samson 3785 Mounting And Operating Instructions

Attaching the positioner

2.3 Attachment to rotary actuators

For the selection of the required mounting
parts, refer to table 6 on page 21.
The positioner can also be attached to rot-
ary actuators in accordance with VDI/VDE
3845 by using the mounting parts and ac-
cessories listed in Table 6. In this arrange-
ment, the actuator's rotary motion is con-
verted via the cam disk on the actuator
shaft and the follower roll of the positioner
lever to a linear motion required by the posi-
tioner's inductive displacement sensor sys-
tem.
Each cam disk is suitable for two curves: for
angles of rotation from 0 to 90° and for
0 to 120°.
For double-acting, springless rotary actua-
tors, it is necessary that a reversing ampli-
fier be attached to the connected side of the
positioner, see chapter 2.3.4.
If the positioner is attached to a SAMSON
Type 3278 Rotary Actuator, the air ex-
hausted from the positioner is admitted to
the inside of the actuator and the chamber
behind the diaphragm. No additional tub-
ing is required. If the positioner is attached
to actuators of other manufacturers
(NAMUR), the air is applied to the chamber
behind the diaphragm through a tube as-
sembly and a tee, connected between actua-
tor and intermediate piece.
18
EB 8382-1 EN
2.3.1 Mounting the cam follower
roll lever
1. Place lever with the attached roll (35)
on the transmission lever (37) and se-
cure it with the enclosed screws (38)
and washers.

2.3.2 Mounting the intermediate piece

SAMSON Type 3278 Actuator:
1. Screw adapter (36) to the free end of
the rotary actuator shaft, using two
screws.
2. Position intermediate piece (34) on the
actuator case and secure, using two
screws. Align intermediate piece of the
positioner so that the air connections of
the positioner face towards the dia-
phragm case side.
Actuators of other manufacturers:
1. Position complete intermediate piece
(34, 42 and 44) on fixing level 1 of the
bracket (VDI/VDE 3845) delivered with
the actuator and fasten with screws.
2. Align cam disk (40) and scale accord-
ing to chapter 2.3.3 and fasten with
screws.
With springless actuators, the reversing am-
plifier (45) must be screwed to the side of
the positioner case. See chapter 2.3.4 for
more details.