The complete component of the hoist.
Crane block or Hook block is considered the complete component of the hoist and it’s linked to the crane by the rope pulleys/sheaves though the rope.
Its design depends on the crane purpose and concept design whereas rope pulleys or sheaves and hook assembly design will be the key factor to achieve customer requirements and expectations. Sheaves must keep a proportional relation and must be symetric to the gravity center of the Crane Block.
Last decades sheaves diameter has been decreased thanks to wire ropes advanced technology using more flexible wire ropes, reducing rope diameter and increasing strengthness thanks to very advanced materials, having decreased the historical factor (rope diameter (d1) x factor=sheave diameter (D).
The number of sheaves in the Hook Block will depend on the total WLL of the Hook Block and individual sheave WLL: falls is called to the twisted rope, whereas 1 sheave has always 2 falls, 2 sheaves have 4 falls…
The fall must have a certain angle for safety reasons: regularly the maximum angle is regulated by International Standards.
Modern Hook Block designs they need to respond to latest customer demands as:
* Easy to dissassemble to exchange hook type and replace inner components and accessories as bearings and sheaves.
* Easy to grease it during maintenance, in order to keep all turning parts lubricated.
Proof Test Load (PTL) is being performed at IRIZAR benches in order to cover a full guarantee to the crane operator.
Complete Maintenance Manual is being delivered to the customer full of recommendations and good practices from the original manufacturer for a safe and long lifetime component.