A forklift (also called lift truck, jitney, hi-lo, fork truck, fork hoist, and forklift truck) is a powered industrial truck used to lift and move materials over short distances. The forklift was developed in the early 20th century by various companies, including Clark, which made transmissions, and Yale & Towne Manufacturing, which made hoists. Since World War II, the use and development of the forklift truck have greatly expanded worldwide. Forklifts have become an indispensable piece of equipment in manufacturing and warehousing. In 2013, the top 20 manufacturers worldwide posted sales of $30.4 billion, with 944,405 machines sold.
The middle nineteenth century through the early 20th century saw the developments that led to today's[when] modern forklifts. The forerunners of the modern forklift were manually-powered hoists that were used to lift loads. In 1906, the Pennsylvania Railroad introduced battery-powered platform trucks for moving luggage at their Altoona, Pennsylvania, train station. World War I saw the development of different types of material-handling equipment in the United Kingdom by Ransomes, Sims & Jefferies of Ipswich. This was in part due to the labor shortages caused by the war. In 1917, Clark in the United States began developing and using powered tractor and powered lift tractors in their factories. In 1919, the Towmotor Company, and Yale & Towne Manufacturing in 1920, entered the lift truck market in the United States. Continuing development and expanded use of the forklift continued through the 1920s and 1930s. The introduction of hydraulic power and the development of the first electric power forklifts, along with the use of standardized pallets in the late 1930s, helped to increase the popularity of forklift trucks.
The start of World War II, like World War I before, spurred the use of forklift trucks in the war effort. Following the war, more efficient methods for storing products in warehouses were being implemented. Warehouses needed more maneuverable forklift trucks that could reach greater heights and new forklift models were made that filled this need. For example, in 1954, a British company named Lansing Bagnall, now part of KION Group, developed what was claimed to be the first narrow-aisle electric-reach truck. The development changed the design of warehouses leading to narrower aisles and higher load-stacking that increased storage capability. During the 1950s and 1960s, operator safety became a concern due to the increasing lifting heights and capacities. Safety features such as load backrests and operator cages, called overhead guards, began to be added to forklifts produced in this era. In the late 1980s, ergonomic design began to be incorporated in new forklift designs to improve operator comfort, reduce injuries and increase productivity. During the 1990s, exhaust emissions from forklift operations began to be addressed which led to emission standards being implemented for forklift manufacturers in various countries. The introduction of AC power forklifts, along with fuel cell technology, are also refinements in continuing forklift development.
Forklifts are rated for loads at a specified maximum weight and a specified forward center of gravity. This information is located on a nameplate provided by the manufacturer, and loads must not exceed these specifications. In many jurisdictions, it is illegal to alter or remove the nameplate without the permission of the forklift manufacturer.
Another critical characteristic of the forklift is its instability. The forklift and load must be considered a unit with a continually varying center of gravity with every movement of the load. A forklift must never negotiate a turn at speed with a raised load, where centrifugal and gravitational forces may combine to cause a tip-over accident. The forklift is designed with a load limit for the forks which is decreased with fork elevation and undercutting of the load (i.e., when a load does not butt against the fork \"L\"). A loading plate for loading reference is usually located on the forklift. A forklift should not be used as a personnel lift without the fitting of specific safety equipment, such as a \"cherry picker\" or \"cage\".
Forklifts are a critical element of warehouses and distribution centers. It is considered imperative that these structures be designed to accommodate their efficient and safe movement. In the case of Drive-In/Drive-Thru Racking, a forklift needs to travel inside a storage bay that is multiple pallet positions deep to place or retrieve a pallet. Often, forklift drivers are guided into the bay by guide rails on the floor and the pallet is placed on cantilevered arms or rails. These maneuvers require well-trained operators. Since every pallet requires the truck to enter the storage structure, damage is more common than with other types of storage. In designing a drive-in system, dimensions of the fork truck, including overall width and mast width, must be carefully considered.
Forklift hydraulics are controlled either with levers directly manipulating the hydraulic valves or by electrically controlled actuators, using smaller \"finger\" levers for control. The latter allows forklift designers more freedom in ergonomic design.
Forklift trucks are available in many variations and load capacities. In a typical warehouse setting, most forklifts have load capacities between one and five tons. Larger machines, up to 50 tons lift capacity, are used for lifting heavier loads, including loaded shipping containers.
In addition to a control to raise and lower the forks (also known as blades or tines), the operator can tilt the mast to compensate for a load's tendency to angle the blades toward the ground and risk slipping off the forks. Tilt also provides a limited ability to operate on non-level ground. Skilled forklift operators annually compete in obstacle and timed challenges at regional forklift rodeos.
Variant on a Rider Stacker forklift, designed for small aisles. They are usually electrically powered. A reach truck's forks can extend to reach the load, hence the name. There are two variants: moving carriage, which is common in North America; and moving mast, which is common in the rest of the world, and generally regarded as safer.
Standard forklifts use a counterweight at the rear of the truck to offset, or counterbalance, the weight of a load carried at the front of the truck. Electric-powered forklifts utilise the weight of the battery as a counterweight and are typically smaller in size as a result.
A counterbalance-type sit-down rider electric forklift fitted with a specialized mast assembly. The mast is capable of rotating 90 degrees, and the forks can then advance like on a reach mechanism, to pick up full pallets. Because the forklift does not have to turn, the aisles can be exceptionally narrow, and if wire guidance is fitted in the floor of the building the machine can almost work on its own. Masts on this type of machine tend to be very high. The higher the racking that can be installed, the higher the density the storage can reach. This sort of storage system is popular in cities where land prices are very high, as by building the racking up to three times higher than normal and using these machines, it is possible to stock a much larger amount of material in a building with a relatively small surface area.
These lifts are found in places like marinas and boat storage facilities. Featuring tall masts, heavy counterweights, and special paint to resist seawater-induced corrosion, they are used to lift boats in and out of storage racks. Once out, the forklift can place the boat into the water, as well as remove it when the boating activity is finished. Marina forklifts are unique among most other forklifts in that they feature a \"negative lift\" cylinder. This type of cylinder allows the forks to actually descend lower than ground level. Such functionality is necessary, given that the ground upon which the forklift operates is higher than the water level below. Additionally, marina forklifts feature some of the longest forks available, with some up to 24 feet long. The forks are also typically coated in rubber to prevent damage to the hull of the boats that rest on them.
Omnidirectional technology (such as Mecanum wheels) can allow a forklift truck to move forward, diagonally and laterally, or in any direction on a surface. An omnidirectional wheel system is able to rotate the truck 360 degrees in its own footprint or strafe sideways without turning the truck cabin.
In order to decrease work wages, reduce operational cost and improve productivity, automated forklifts have also been developed. Automated forklifts are also called forked automated guided vehicles and are already[when] available for sale.
These forklifts use an internal combustion engine modified to run on LPG. The fuel is often stored in a gas cylinder mounted to the rear of the truck. This allows for quick changing of the cylinder once the LPG runs out. LPG trucks are quieter than their diesel counterparts, while offering similar levels of performance.
Powered by lead-acid batteries or, increasingly, lithium-ion batteries; battery-electric types include: cushion-tire forklifts, scissor lifts, order pickers, stackers, reach trucks and pallet jacks. Electric forklifts are primarily used indoors on flat, even surfaces. Batteries prevent the emission of harmful fumes and are recommended for indoor facilities, such as food-processing and healthcare sectors.
Hydrogen fuel cell forklifts are powered by a chemical reaction between hydrogen and oxygen. The reaction is used to generate electricity which can then be stored in a battery and subsequently used to drive electric motors to power the forklift. This method of propulsion produces no local emissions, can be refueled in three minutes, and is often used in refrigerated warehouses as its performance is not degraded by lower temperatures. 153554b96e