Lifting tools are the material handling tools of lifting or top weights, a tool for intermittent work and lifting weights. Most lifting tools in the lifting of the feeding after the beginning of vertical or vertical and horizontal work stroke, to arrive at the destination after unloading, the empty trip to the pickup location, complete a work cycle, and then carry out the second lifting. Generally speaking, lifting tools work, feeding, migration and unloading is in turn, the corresponding agencies work is intermittent.
Lifting tools are mainly used to carry items, equipped with grab bucket can carry coal, ore, food and other scattered materials, equipped with barrels can be lifted liquid steel and other liquids. Some lifting tools such as elevators can also be used for manned. In some use occasions, lifting equipment is the main operating tool, such as the crane at port and station handling materials is the main lifting tool.
The use of various lifting tools is different, there are great differences in structure, but all have the lifting mechanism to achieve the basic movements. Items can be hung up and down by wire rope or lifting chains, and can also be lifted by screws or other rigid pieces.
Lifting tools can be divided into light small lifting equipment, hoist and overhead monorail systems. Light small lifting equipment mainly includes lifting pulley, hanging sling, Jack, triangle-type hand-pulling gourd, electric hoist and common winch, most of the small size, light weight, easy to use. In addition to electric hoist, the vast majority of human-driven, suitable for the work of heavy occasions.
They can be used separately, and some can also be used. Some light small lifting equipment is very large, such as hydraulic jack lifting capacity has reached 750 tons. Mine hoist and hopper lifts are mainly vertical or near-vertical lifting movements, with fixed lifting routes. Overhead monorail system has a rigid hanging track to form the line, the material can be transported to the plant parts, also can be extended to the outside of the plant.
The main performance parameter characterizing the basic working ability of lifting tools is the weight and work level. ① weight is the maximum weight of a weight that is permitted to be lifted under prescribed working conditions, i.e. the rated weight. Usually with permanent magnet sucker (see Permanent Magnet lifter), the weight should also include the weight of the permanent magnet sucker. The working level is the performance parameter reflecting the general working condition of lifting tools, which is an important basis for designing and selecting lifting tools. It is determined by the total number of cycles and load states that the lifting tool needs to complete within the required period of use. The working cycle is also an important parameter for the regular and repetitive lifting tools such as the electric hoist, the hand pulling hoist used in the overhead warehouse and the hopper elevator for the blast furnace feeding on the ship cargo. The work cycle refers to the time required to complete a work cycle, depending on the speed of the organization’s work and the distance of the handling. The lifting tools are sometimes also used as an important parameter of productivity, usually expressed by the lifting volume of an hourly completion. Nowadays, efficiency is the first choice, followed by the appearance and quality.