Bridge cranes or overhead cranes are a type of industrial material handling crane making use of a line and hook device which runs on a horizontal beam running along two widely separated rails. Several overhead cranes can be found inside a long factory building and they could run along the building's two long walls, similar to a gantry crane.
Normally, overhead cranes consist of either a single beam or double beam construction. These could be made by using either a more complex girder style or typical steel beams. The single bridge box girder crane is complete together with the system and the hoist and is operated utilizing a control pendant. When the application needs heavier capacity systems for at least ten tons, double girder bridge cranes are more common.
With the girder box configuration, one major advantage is the lower deadweight with a stronger integrity of the overall system. Another advantage would be the hoist so as to lift the items and the bridge which spans the area covered by the crane, along with a trolley to be able to move along the bridge.
Overhead cranes are more frequently used in the steel business. The steel is dealt with using this crane at each and every level of the manufacturing method until the product is shipped from the factory. The crane is likewise responsible for pouring raw materials into a furnace and hot steel is then stored for cooling making use of an overhead crane. As soon as the coils are finished they are loaded onto trucks and trains via overhead crane. The stamper or fabricator likewise depends on overhead cranes in order to handle steel within the factory.
Overhead cranes are usually utilized in the automobile industry for the handling of raw material. There are smaller workstation cranes which are meant to handle lighter loads inside work areas like for example in CNC shops and sawmills.
Bridge cranes could be seen in virtually all paper mills. They are utilized for usual repairs needing removal of heavy press rolls as well as various machinery. Some of the cast iron paper drying drums as well as other pieces of specialized equipment weigh as heavy as seventy tons. The bridge cranes are actually used in the initial construction of the paper machinery in order to facilitate installation of these very heavy objects.
The price of a bridge crane can be largely offset in numerous cases with savings incurred from not renting mobile cranes when a plant is being constructed that makes use of plenty of heavy process equipment.
The Rotary Overhead crane has one end of the bridge attached on a fixed pivot and the other end carried on an annular track. The bridge traverses the circular area underneath. Rotary Overhead cranes provide improvement over a Jib crane by making it possible to supply a longer reach while eliminating lateral strains on the building walls.
Demag Cranes & Components Corp. was among the first businesses to mass produce steam powered cranes. The now defunct Alliance Machines were the second business to mass produce cranes. Alliance holds an AISE citation for one of the first cranes in the United States market. This particular crane was used in service until about the year 1980 and has been retired into a museum in Birmingham, Alabama.
Several innovations have come and gone ever since the first cranes, for instance, the Weston load brake is at present practically obsolete, whereas the wire rope hoist is still common. The wire rope hoist was at first hoisted to contain components mated together so as to form a built-up style hoist. These super industrial hoists are utilized for heavy-duty applications such as steel coil handling for instance. They are also popular for users who desire better quality and long life from their machinery. These built up hoists even provide for easier upkeep.
Nowadays, many hoists are package hoists. This means they are made as one unit in a single housing that is typically designed for ten years of life. This particular estimate is based on an industry standard wear and tear when calculating actual life.
The Material Handling Industry in North America, there are very few governing bodies in the industry. The Crane Manufacturers Association of America is represented by the Overhead Alliance that also represents HMI or likewise referred to as Hoist Manufacturers Institute and MMA or otherwise referred to as Monorail Manufacturers Association. The members of this particular organization are marketing representatives of the member companies and these product counsels have joined forces to make marketing materials to be able to raise the awareness of the advantages to overhead lifting.