Three-point Hitch
From RitchieWiki
The three-point hitch is a linkage system designed for farm tractors to connect implements and attachments to the rear of the machine. It consists of three hitch points (one upper and two lower), all operated by hydraulics. The upper hitch controls the draft (or depth) of the attachment while the two lower hitches are able to raise and lower the attachment as needed.
The key benefit provided by the three-point hitch is that it transfers the weight and drag of the attachment to the rear wheels of the tractor, which increases traction. Thus “traction is maximized when pulling is most difficult.”[1] It also made connecting and disconnecting attachments a quicker and easier process
[edit] History
Initially, each tractor had its own linkage system, requiring manufacturers to provide specific attachments for their tractors. These simple single tow-hitch systems resulted in a lot of drag, often causing tractors to stall or even flip over.
So, an Irish tractor salesman named Harry Ferguson, with a talent for engineering, began developing a new system. He experimented with new link systems throughout the 1920s and 1930s. His first new design was the Duplex Hitch. It consisted of two nearly parallel struts, which resisted the plow’s tendency to rise when met with resistance. Instead, it counteracted with downward force on the attachment. However, despite the advancements made by the Duplex Hitch, it did not have any draft control. Draft control would allow the implement to automatically lift when it reached very tough soil, decreasing drag, until the spot was passed.
By adding a hydraulically powered upper hitch, Ferguson was able to solve the draft problem. His new system was called the three-point hitch.
The hitch was first attached to a David Brown tractor in 1933, creating the Ferguson-Brown model A. By 1937, sales had dropped and relations between Brown and Ferguson had become hostile.
Ferguson decided to shop his system to Henry Ford in 1939 and together they released the Ford model 2N, 9N, and 8N. Eventually this partnership also dissolved, resulting in a lawsuit over royalties.
By 1960, Ferguson’s patent had expired and the three-point hitch was made the industry standard, which it still stands today.
