Manual lever hoist is a small light ideal for manual lifting tools, with a light weight, high level, better security, high reliability and low failure rate, low noise, braking torque characteristics. Why shoupan hyacinth can save effort then? These may have a lot of people don't know, Yi Wu Junwei shoupan hyacinth labour-saving principle and Jack is different. But they are also the conservation of energy, what is the process we use Hulu? In fact, not only are a practical application of pulley. Then we see how pulleys are labour-saving it:


Donghualun object, force is equal on both sides of the rope, and are guided by the physical half of gravity, and needed only to pull one side of the man just under half of the gravity of the object, while the other half of gravity by fixed objects are exposed by the other end of the rope. Is just one way to torque balance, increasing the torque can be reduced, is the lever principle.