Review of historic forklifts
Introduction
A forklift, also known as forklift, self-elevator or forklift,[1][2] (colloquially, bull), (forklift in English), is a rear-balanced vehicle that, using two forks, is used to raise, lower and transport pallets, containers and other loads. In addition, forks can be used with different lifting devices, such as slings and pulleys.[3].
Given the great diversity of configurations and types of vehicles that exist within the field of load handling and lifting, to have this consideration it must be a vehicle that supports and transports the load cantilevered in front of the front axle, and the upward and downward movement of the load is carried out by sliding along a mast.[4].
Within this denomination, they range from small and compact models barely designed to lift 1000 kg to large versions - used, for example, in ports - capable of handling a loaded container (2 x TEU "TEU (unit of measurement)") (that is, they move the entire load of a truck in one go).[5].
History
The first prototype of a forklift was created by Henry Waterman") in 1850.[6] It was a platform attached to a cable. This model inspired Otis to invent the elevator, an elevator with a toothed system, which allowed it to cushion its fall in case its cable was cut. It was in 1915 when the first forklifts emerged capable of moving loads both horizontally and vertically. At the time of the First World War, a platform was designed that could raising and lowering the goods thanks to a lifting mechanism, but, nevertheless, it was Clark in 1917 who came up with the idea of the operator working sitting on the forklift itself.
Starting in 1920, hydraulic power was introduced to lift loads, and in 1923 Yale produced the first forklift truck fitted with forks and a lifting mast. In 1954, the British company called Lansing Bagnall developed the modern forklift as we know it today.
Furthermore, it must be recognized that this type of machines have been pioneers in the use of electrical energy for mobility.[7].
Description
It has two flat parallel bars on its front, which are inserted into the pallet (under the load), called "forks" (sometimes also colloquially "nails"), mounted on a support that slides vertically along a mast, thereby achieving the lifting and lowering movement of the load. The separation between forks is variable to adapt to different pallet sizes or loads; The fork support has a small lateral displacement (to the right and left) to perform pallet approach maneuvers or centering the claws with the load. The rear wheels are steerable (steering) with a large turning angle to facilitate maneuverability in narrow spaces. Usually the front wheels are the driving or propelling wheels; There are also 4x4 versions for use outdoors or on construction sites.[8].