Block and tackle, it could be one of the most important tools that you must have in your collection. It is one of those pieces of equipment that has far more uses than you could have ever imagined, and it is not as expensive as you think.
A block and tackle include a series of pulley wheels called sheaves that are combined together in one wooden or metal housing called the block. This piece of equipment can lift your machinery and even hoist building materials. Once you understand the main functional facts of correctly matching the rope and block, and how leverage works with the changes in the number of pulley sheaves that are being used, then you can estimate the extent of its uses. If you want to lift twice as much weight, then you should double the number of pulleys you are using. The force required lessens proportionately with the amount of pulleys or the loops used during the hoist.
Pulling Tools – The Big Benefit
It is important to note that sheave size affects wire rope strength. Severe bending is a major cause of short rope life and damage. The repeated bending and straightening of the wire rope causes a recurrent change of stress known as fatiguing. To avoid fatiguing, strive for a larger sheave diameter so that there is less wear and tear on the rope and you will have a much greater efficiency strength as well.
Sheave Blocks and the Right Combination
A sheave block for wire rope can be used in many different combinations if you want to increase the lifting or the pulling capacity. You should always take safety measures to ensure that the structure, along with all of the hook equipment is of adequate capacity. Some questions to ask yourself would be: What is the capacity that you will need? Or do you need a multi-sheave block? The diameter of the rope you are using is equally important, as well as the use of slings or shackles.
Whether you call them pulleys, sheaves, or blocks, these ancient devices make light work of all those heavy loads.
