A Forklift Truck (also called a lift truck, a high/low, a stacker-truck, trailer loader, sideloader, fork truck, tow-motor or a fork hoist) is a powered industrial truck used to lift and transport materials. The modern forklift was developed in the 1920s by various companies including the transmission manufacturing company Clark and the hoist company Yale & Towne Manufacturing. The forklift has since become an indispensable piece of equipment in manufacturing and warehousing operations.
The middle nineteenth century through the early twentieth century saw the developments that led to today's modern forklifts. The Pennsylvania Railroad in 1906 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 and Jeffries 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. 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. New forklift models were made that filled this need. In 1956 Toyota introduced its first lift truck model, the Model LA, in Japan and sold its first forklift in the United States in 1967.
Replacing or Adding AttachmentsEdit
It's possible to replace an existing attachment or add one to a lift that doesn't already have one. Considerations include forklift type, capacity, carriage type, and number of hydraulic functions (that power the attachment features). As mentioned in the preceding section, replacing or adding an attachment may reduce (down-rate) the safe lifting capacity of the forklift truck (See also General operations, below).
Forklift attachment manufacturers offer on-line calculators to estimate the safe lifting capacity when using a particular attachment, but only the forklift truck manufacturer can give accurate lifting capacities. Before installing any attachment, you should contact your local authorized dealer of your forklift brand, and ask them to begin re-rating your lift according to the attachment you want to install. Once re-rated you should receive a new factory authorized specification plate to replace the original currently found on your lift.
Adding Hydraulic FunctionsEdit
In the context of attachments, a hydraulic function consists of a valve on the forklift with a lever near the operator that provides two passages of pressurized hydraulic oil to power the attachment features. Sometimes an attachment has more features than your forklift has hydraulic functions, and one or more need to be added.
There are many ways of adding hydraulic functions (also known as adding a valve). The forklift manufacturer makes valves and hose routing accessories, but the parts and labor to install can be prohibitively expensive. Other ways include adding a solenoid valve in conjunction with a hose or cable reel that diverts oil flow from an existing function. However, hose and cable reels can block the operator's view and are problematic, easily damaged. The Ditto Valve kit uses a solenoid valve and special HydWire hoses, in which the wire reinforcing braid doubles as an electrical conduit. These hoses replace those already on the forklift, nesting in the original reeving, keeping it safe from damage and out of the operators field of vision.
Forklift Control and CapabilitiesEdit
Forklift trucks are available in many variations and load capacities. In a typical warehouse setting most forklifts used have load capacities between one to 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.