98
GENERAL
x
ROPES
Dangerous rope winding .
Fast wear of the groove Excessively tight winding and the rope .
on the drum or overlapping .
Deflection Longevity angle factor 0° 1 1° 0.9
2° 0.75
3° 0.70
4° 0.67
An excessive deflection angle causes : Tests made by Stuttgart University indicate the following shortening of the rope life according to the slant angle :
L L
R' R'
R R D
Tambour lisse Tambour rainuré Angle à Angle à maximum maximum 1° à 1°30 2° à 1°30 1° à 1°30 2° 2°
L L
R' R'
R R D D
Tambour lisse Tambour rainuré Angle à Angle à maximum maximum 1° à 1°30 2° 1° à 1°30 1° à 1°30 2° 2° = 1.5°
max on smooth drum .
= 2° max on grooved drum .
In practice , the minimum distance
D
must be :
D
min = 20 x
L
treuil 1t treuil 1t treuil 1t treuil 1t brin 1 brin 2 brins 2 brins 1t 2t 2t 2t 22t 2t 3t 33t 3t 1t 1t 1t 1t 1t 1t 1t 1t 1t 1t Principle of reeving .
x Use with pulley or pulley block x Deflection angle 1 fall 2 falls 1 t winch 1 t winch 2t 2t 3t 3t 1t 1t 1t 1t 1t Smooth drum Grooved drum Angle 1° to 1°30 max .
to to Angle to 2° max .
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