Positioning Mechanism - Planmeca Proline EC pan Technical Manual

Chapter I - FUNCTIONAL DESCRIPTION

1.7 Positioning mechanism

The fixed frame of the mechanism is the installation plate (Fig. 7, 1), to which the mobile
frame is attached with linear bearings through axes (Fig. 7, 2). All parts entering into contact
with the patient, i.e. patient handles, chin and/or bite support/s (Fig. 7, 3 and 4) and temple
supports (Fig. 7, 5) are fixed to the frame (Fig. 7, 6) so that they move together with the frame.
Linear movement is driven by a stepper motor. Primary drive is realized by cogged belt and
secondary drive by a screw. The screw is connected to a drawing nut (Fig. 7, 7) attached to
the frame (Fig. 7, 6). The adjustment of the linear movement position reference is realized
with a Hall-detector. The detector is located on a PCB card (Fig. 7, 8) and the magnet is
located on a bar attached to the installation plate (Fig. 7, 1). The microprocessor controls the
linear movement.
The cranks (Fig. 7, 8) of the temple supports are attached with bearings to the frame (Fig. 7,
6) so that they can rotate freely. The movement of the cranks is synchronized to each other
with gearwheel quadrants. Clearance of the quadrants is adjusted with an adjustment piece
(Fig. 7, 9). The force closing the temple supports is produced with a spring. The force is trans-
ferred to the quadrant through lugs (Fig. 7, 10). The force opening the temple supports is pro-
duced with the step motor to a lever (Fig. 7, 11) through a drive screw (Fig. 7, 12) and a drive
nut. The lever transfers the force over to the temple supports through an adjustment screw.
The limit switch is the Hall detector on the PCB card (Fig. 7, 7). The detector gets an impulse
from a magnet located on the lever (Fig. 7, 11).
I-8 Planmeca Proline EC X-ray unit
MECHANICAL CONSTRUCTION AND OPERATION
Technical Manual