Three-point hitch

Three-point hitch

The three-point hitch (British English: three-point linkage) most often refers to the way ploughs and other implements are attached to an agricultural tractor. Three point attachment is the simplest and the only statically definite way of joining two bodies in engineering. The implements can be either hooked on to the hitches of the tractor, as well as implements that are pulled and are connected to the hitches. The three points resemble either a triangle, or the letter A. Its utility and simplicity has made it an industry standard.


The three-point hitch is made up of several components working together. These include the tractor's hydraulic system, attaching points, the lifting arms, and stabilizers.

Three-point hitches are composed of three movable arms. The two outer arms - the hitch lifting arms - are controlled by the hydraulic system, and provide lifting, lowering, and even tilting to the arms. The center arm - called the top link - is movable, but is usually not powered by the tractor's hydraulic system. Each arm has an attachment device to connect implements to the hitch.

Each hitch has attachment holes for attaching implements, and the implement has posts that fit through the holes. The implement is secured by placing a pin on the ends of the posts.

The hitch lifting arms are powered by the tractor's own hydraulic system. The hydraulic system is controlled by the operator, and usually a variety of settings are available.

There are several different hitch systems, called categories. Category Zero hitches are used with small farm or garden tractors. Category III hitches are found on the larger farm tractors, or those above 90hp.

The primary benefit of the three point hitch system is to transfer the weight and stress of an implement to the rear wheels of a tractor.


Harry Ferguson patented the three-point 'linkage' for agricultural tractors in Britain in 1926. His credit does not lie in invention of the device, but in realization of the importance of rigid attachment of the plough to the tractor. He is also attributed with several innovations to this device (e.g. hydraulic lift) which made this system workable, effective, and desirable to the point of using it on mass marketed tractors (e.g. the Ford 9N).

Before the 1960s, each manufacturer used their own systems for hitching, or attaching their implements to their tractors. Commonplace was the two-point hitch system which could not effectively be used for lifting many implements. At this time, farmers would have to purchase the same brand implements as their tractor to be able to correctly hook up the implement. If a farmer needed to use a different brand implement with the tractor an adaptation kit - which were typically clumsy, ill-fitting, or unsafe - had to be installed.

In the 1960s, tractor and implement manufacturers would eventually agree on the three-point hitch as the one standard system to hitch implements to tractors. As patents on technology expired, the manufacturers were able to refine the system and create useful modifications. Now, nearly all manufacturers have adopted some standardized [ [ ISO 730-1] ] form of the modern three-point hitch system; many companies also offer safe adaptation fits for converting the non-standard hitch systems to the three-point hitch system.

ee also

* Overrunning clutch
* Power take-off

External links

* [ The inventor, Harry Ferguson]
* [ Three-point linkage model]
* [ Massey-Ferguson Tractor Site]
* [ Explanation of the categories]
* [ Additional explanation of categories]

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • The Hitch-Hiker (The Twilight Zone) — Infobox Television episode Title = The Hitch Hiker Series = The Twilight Zone Caption = Leonard Strong as the Hitch Hiker Season = 1 Episode = 16 Airdate = January 22, 1960 Production = 173 3612 Writer =Rod Serling (story by Lucille Fletcher)… …   Wikipedia

  • Tractor — This article is about a vehicle used in agriculture or construction. For the power unit of a semi trailer truck (articulated lorry), see tractor unit. For other uses, see Tractor (disambiguation) …   Wikipedia

  • Farmall tractor — The Farmall was the name of a tractor and later a brand name for tractors manufactured by International Harvester. The original Farmall was the first general purpose tractor with narrowly spaced front wheels. The tricycle front wheel design… …   Wikipedia

  • Ferguson Company — In about 1934, in company with David Brown, Harry Ferguson formed the Ferguson Brown Company and the two men produced the Model A Ferguson Brown tractor with a Ferguson designed hydraulic hitch. Ferguson surmised that the tractor hitch was the… …   Wikipedia

  • Ford N Series Tractors — The first of the N Series of Ford tractors was the 9N. It included the first three point hitch system on tractors, in the United States (Ferguson had used it on the Ferguson Brown tractor built for him by David Brown Ltd. in the UK). A design… …   Wikipedia

  • Brush hog — A brush hog [ [ Definition of brush hog] , Dave s Garden.] is a heavily built rotary mower. Typically these mowers attach to the back of a farm tractor using the three point hitch and are driven via the Power… …   Wikipedia

  • Cultivator — F210 Honda tiller 1949 Farmall C with C 254 A two row cultivator …   Wikipedia

  • Dreipunktkupplung — Dreipunkt Hubhydraulik an einem Deutz Traktor Bj. ca. 1965 Eine Dreipunkthydraulik (engl.: three point hitch) oder ein hydraulischer Kraftheber ist eine Vorrichtung, um Anbaugeräte (Arbeitsgeräte) an den Traktor anzukuppeln und anzuheben. Das… …   Deutsch Wikipedia

  • Elektronische Hubwerksregelung — Dreipunkt Hubhydraulik an einem Deutz Traktor Bj. ca. 1965 Eine Dreipunkthydraulik (engl.: three point hitch) oder ein hydraulischer Kraftheber ist eine Vorrichtung, um Anbaugeräte (Arbeitsgeräte) an den Traktor anzukuppeln und anzuheben. Das… …   Deutsch Wikipedia

  • Linkage (mechanical) — This article is about assemblies of links designed to manage forces and movement. For other uses, see Linkage. Variable stroke engine (Autocar Handbook, Ninth edition) A mechanical linkage is an assembly of bodies connected together to manage… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.