? Pulley series 
 According to the number of rounds into a single door pulley, two-door pulley and door pulley. Connection of the trochlea and hanging objects can be divided into the hook type, chain, ring, rings - and four hanger style. Small and medium pulley to a hook type, chain ring and the rings style, while the large pulley rings type and hanging beam. Contact of the wheel and the shaft can be divided into different axle mounted between the sliding bearings and rolling bearing two kinds. Points, according to the splint whether you can open to opening pulley and pulley closed. Opening tackle of plywood can be open, easy to installed ropes are single door pulley, it can be used to foot as a guide pulley with the end of the derrick. Is divided into the way the use of fixed pulley and move the pulley. Easy to use, versatile, can be manual, motorized. Mainly used in the production and construction of factories, mines, agriculture, electricity, construction, machine installation of piers, docks, warehouses, cargo lifting. 
 Lifting block 
 Is an important tool for the lifting of his simple structure, easy to use, able to repeatedly change the direction of traction wire rope pulley and pulley block and lifting or moving the operation object, in particular, is jointly formed by the pulley block and tackle, with the hoist, mast or other lifting machinery, widely used in the construction, installation and product specifications from the 0.03-320T, the gear train from a single round to pick up the round, the crane has a hook, chain, ring, rings, lifting beam four kinds to choose from. 
 Lifting tackle knowledge: 
 1, the pulley is a simple vertical lifting heavy objects, lifting machinery. Weight, compact structure. There are two kinds of manual pulley and electric pulley. 
 ① manual pulley. Driven by human traction chain, Worm drive chain reel, heavy object lifting. Load-made brake, load the heavier braking torque to the greater safety and reliability. The scope of work is linked to a vertical line. 
 Nylon wheel, aluminum lifting tackle: 
 Uses: Suitable for lifting towers, stringing, hoisting equipment, and live operations. 
 Features: light weight, good wear resistance of the wheels, wire rope, rope injury. The form of a hook, ring, single door, double door. 
 ② electric pulley. By the motor-driven gear mechanism, the rope reel and hook pulleys, the heavy object to lift. Rope reel housing, associated with motor and gear drive mechanism with a brake. The middle of the shell upper lug. Hang fixed vertical lifting heavy objects. Pulley can also be hung on the run a small car, the running load car, driving along the overhead track, transportation of materials in the workshop internally or between the workshop and the workshop.