1) Lifting tools are usually small in size, simple in structure, capable of lifting movements and horizontal movements.
2) lifting gear lifting a variety of heavy objects, the load is changing. Some heavy objects weighing hundreds of tons or even thousands of tons, and some objects up to tens of meters, the shape is also very irregular, there are scattered, hot melt state, flammable and explosive dangerous goods, lifting process complex Danger.
3) part of the lifting gear, need to operate in a larger space, and some to install rails and wheels (such as tower crane, bridge crane, etc.); some to install tires or crawlers walking on the ground (such as car cranes , Crawler, etc.); some need to walk on the rope (such as passenger, cargo aerial ropeway), the larger space, once the impact of the scope of the accident is also larger.
4) Some lifting tools need direct transport personnel in the rails, platforms or wire rope to do lifting movements (such as elevators, lifting platform, etc.), its reliability directly affect personal safety.
5) Lifting tools exposed, the activities of more parts, and often with the lifting operations personnel in direct contact (such as hooks, wire rope, etc.), potentially many occasional risk factors.
6) complex operating environment. From the large steel joint enterprises, to the modern port, construction site, railway hub, tourist resort, have lifting tools in operation; workplace often encounter high temperature, high pressure, flammable and explosive, transmission lines, strong magnetic and other risk factors , Posing a threat to equipment and operators.
7) Lifting tool operations often require more people to cooperate with each other. An operation, requiring command, strapping, driving and other operating personnel with skilled, coordinated action, mutual care. Operators should have the ability to handle on-site emergencies. There is a great deal of difficulty in the close cooperation between multiple operators.
Lifting tool of the above characteristics, decided that it has a great relationship with the safety of production. If there is a slight negligence in the design, manufacture, installation and maintenance of the lifting gear, it may result in casualties or equipment accidents. On the one hand caused the casualties, on the other hand will cause great economic losses.
Lifting operations are an industrial process that transfers tooling equipment or other objects from one place to another.
Lifting tools according to the structure can be divided into light and small lifting equipment, hoists and overhead monorail systems and other categories. Light and small lifting equipment, including lifting tackle, spreader, jack,
, Electric hoist and ordinary winch, mostly small size, light weight, easy to use. In addition to electric hoist, the vast majority of manpower-driven, suitable for work is not heavy occasions.
The main performance parameters that characterize the basic working capacity of the lifting tool are the weight and the work level. ① The weight is the maximum weight of the weight that is allowed to be lifted under the specified working conditions, that is, the rated weight. Generally with permanent magnet sucker (see permanent lifting), the weight should also include the weight of permanent magnet sucker. ② work level is to reflect the overall working conditions of the lifting tool performance parameters, is the design and selection of lifting tools important basis. It is determined by the total number of cycles and the state of the load required by the lifting tool during the required use period. The working cycle is also an important parameter for heavy-duty lifting tools such as electric hoists for loading and unloading ship's cargo on the wharf, chain hoists for elevated warehouses and hopper lifts for blast furnace feeding. The duty cycle refers to the time required to complete a work cycle, which depends on the speed of the organization and is related to the handling distance. The above-mentioned lifting appliances are sometimes also used as an important parameter of productivity, usually expressed in terms of the amount of lift per hour. In today's use, efficiency is preferred, followed by appearance, quality.