Planmeca Proline XC, Technical Manual, Page: 246 / 258

Chapter I - FUNCTIONAL DESCRIPTION
I-10 Planmeca Proline XC X-ray unit
MECHANICAL CONSTRUCTION AND OPERATION
Technical Manual
1.8 Height adjustment mechanism
The vertical part of the Z-carriage is supported to the groove of the column (Fig. 8, 1) with 8
wheels. Sideways it is supported with wheels (Fig. 8, 15). There are four more wheels (Fig. 8,
11) in 90 ° angle. In vertical direction the carriage is supported by wires through pulleys (Fig.
8, 12). In the upper part of the column there is a top trim cover (Fig. 8, 28) to the lugs (Fig. 8,
22) of which pulleys (Fig. 8, 27) are attached with bearings.
A direct-current motor (Fig. 8, 44) draws the drive pulleys through a worm gear transmission
(Fig. 8, 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. 8, 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. 8, 2) compensates the weight of the Z-carriage. Cables are con-
nected to the counterweight through a compensating lever (Fig. 8, 7). The compensating
lever compensates 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. 8, 5)
to the tracks of the column.