Lift machine

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B8 Lift machine
B8.1. Methods of driving the car and the counterweight
B8.1.1. The two following driving methods may be used:
by traction (use of sheaves and ropes); or
by fixed attachment (use of a winding drum and ropes, or
chain drive wheels and chains).
B8.2. Use of belts to drive the machine
B8.2.l. Belts may be used to couple the motor or motors to
the rotating part subjected to the mechanical brake action, pro-
vided that the belts are of the "V" or toothed type and that there
is at least one more than the minimum number determined by
calculation.
B8.3. Use of overhung sheaves or pulleys
B8.3.1. When overhung sheaves or pulleys are used, arrange-
ments should be made to prevent the ropes from leaving the
sheave or pulley grooves.
B8.4. Brake system
B8.4.l. The lift should be fitted with a brake system which
must include a mechanical brake; additional means of deceleration
may be provided, for example dynamic braking.
B8.4.2. The brake system should act automatically in case of
failure of the electric supply to the machine or the controls.
B8.4.3. The brake system should be capable of stopping a
descending car travelling at contract speed with its contract load
increased by 25 per cent.
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