Block and Tackle
From DT Online
Revision as of 14:07, 26 August 2016 by DT Online (Added animations)
A Block and Tackle comprises a number of pulleys grouped together in blocks or ‘sheaves’ such that one block is fixed and the other is made moveable by means of a single continuous rope, or similar, threaded around them. In this configuration, the load is shared between the number of ropes threaded between the two blocks.
Features and Applications
In the Block and Tackle shown there appears to be 3 ropes on each side joining the two blocks together and so its Mechanical Advantage would be 6 - i.e. pulling down on the rope with a force of 100kg would enable a load of 600kg to be lifted (assuming there are no losses due to friction).
|Lifting Tackle - Mechanical Advantage = 4 (number of the cable branches that suspend the weight or twice number of movable pulleys)||Using a series of pulleys - Mechanical Advantage = 8 (each pulley halves the load).|
|Panel Gripper||Door and Board Lifter||Sack Trolley||Lifting Tongs||Drywall Board Hoist||Engine Hoist||Block and Tackle||Chain Block Hoist||Hand Wire Winch|