Cassette Mechanism, Planmeca Proline Xc Pan/Ceph X-Ray Unit - Planmeca Proline XC Technical Manual

MECHANICAL CONSTRUCTION AND OPERATION
1.3 Cassette mechanism, Planmeca Proline XC Pan/Ceph X-
ray unit
Technical Manual
The primary function of the cassette mechanism is to enable controlled linear movement of
the film cassette across the radiation beam synchronically in relation to the rotation move-
ment. Besides, the cassette mechanism has certain secondary functions such as secondary
collimator which prevents the radiation scattering from patient from exposing the film and
Frankfort positioning light reflector which produces a horizontal light beam to facilitate patient
positioning.
The assembly (Fig. 4, 1) is the frame of the cassette mechanism. A carriage (Fig. 4, 2) is
attached with bearings and axles (Fig. 4, 3 and 4) to the frame. The panoramic carriage is
locked to the frame.
The cassette holder (Fig. 4, 5) is attached with linear bearings to the carriage through axle
(Fig. 4, 6) and support wheel (Fig. 4, 7). The cassette carriage is driven by an friction wheel
(Fig. 4, 8) which is in contact with the top surface of the carriage.
The lateral force caused by the cassette holder, the weight of the film cassette and the load-
ing spring of the driving wheel is compensated by a support wheel in the carriage (Fig. 4, 2).
The cassette holder rolls against the support wheel. The secondary collimator (Fig. 4, 9) is
attached to the carriage (Fig. 4, 2). Commanded by the microprocessor a stepper motor (Fig.
4, 10) rotates the friction wheel analogically with the rotation mechanism through worm gear
transmission.
The cassette mechanism is shown below.
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Figure 4
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Chapter I - FUNCTIONAL DESCRIPTION
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Planmeca Proline XC X-ray unit I-5
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