Planmeca Proline CC, Техническое руководство

Страница: 193 / 207

Chapter I - FUNCTIONAL DESCRIPTION
Planmeca Proline CC panoramic x-ray I-7
Technical Manual
1.6 Height adjustment mechanism
The vertical part of the Z-carriage is supported to the groove of the column (Fig. 6, 1) with 8
wheels. Sideways it is supported with wheels (Fig. 6, 15). There are four more wheels (Fig. 6, 11)
in 90 ° angle. In vertical direction the carriage is supported by wires through pulleys (Fig. 6, 12).
In the upper part of the column there is a top trim cover (Fig. 6, 28) to the lugs (Fig. 6, 22) of
which pulleys (Fig. 6, 27) are attached with bearings.
A direct-current motor (Fig. 6, 44) draws the drive pulleys through a worm gear transmission (Fig.
6, 10). In practice only one of the two pulleys is closely connected to the secondary axle of the
transmission whereas the other is freely assembled with bearings. This means that one of the
two cables (Fig. 6, 4) moves the Z-carriage while the other cable only partially carries the weight
of the Z-carriage. One cable would be strong enough to carry the Z-carriage in case the other
should break.
The counterweight (Fig. 6, 2) compensates the weight of the Z-carriage. Cables are connected to
the counterweight through a compensating lever (Fig. 6, 7). The compensating lever compen-
sates small differences in length of the cables and ensures that both cables can carry the weight
of the Z-carriage. The counterweight is attached with four wheels (Fig. 6, 5) to the tracks of the
column.
A Hall detector in the vertical part of the Z-carriage is the limit switch for the Z-carriage move-
ment. The detector gets impulses from magnets (Fig. 6, 32) of the column. Commandment of
height adjustment motor is described in section “Motors” on page I-10.
Figure 6
1
5
7
11
12
11
4
27
10
28
22
15
1
27
20
44
32