- Tow hitch
A tow hitch (or tow bar) is a device attached to the
chassisof a vehicle for towingor a towbar to an aircraftnose gear, or paired main gears.
It can take the form of a tow-ball to allow and articulation of a trailer, or a tow
pinand jawwith a trailer loop - often used for large or agricultural vehicles where slack in the pivot pin allows the same movements. Another category is the towing pintle used on military vehicles worldwide.
In the U.S. the vehicle attachment is known as the "trailer hitch". Trailer hitches come in two main configurations: receiver type and fixed-drawbar type. Receiver-type hitches consist of a portion that mounts to the frame of the vehicle that has a rearward facing opening that accepts removable ball mounts, hitch bike racks, cargo carriers, or other hitch mounted accessories. Fixed-drawbar hitches are typically built as one piece, have an integrated hole for the trailer ball, and are generally not compatible with aftermarket hitch accessories.
A trailer hitch typically bolts to the chassis of the vehicle. In the U.S. there are a few common classes: I, II, III, IV, and V that are defined by the SAE. : Class I - up to convert|2000|lb|0|adj=off, and II - up to convert|3500|lb|0|abbr=on, are for designed for light loads. : Class III - up to convert|5000|lb|0|adj=off, and IV - up to convert|10000|lb|0|abbr=on, can accommodate much larger trailers such as campers, boats, etc.
Receiver-type hitches are typically offered with a square receiver opening of 1.25 inches / 31.7 mm x 1.25 inches (for Class I/II) or 2 inches / 50.1 mm x 2 inches (for Class III/IV/V). Some Class IV/V hitches are available in 2.5 inch / 63.5 mm x 2.5 inch opening sizes.
The trailer tongue (U.S.) or coupling (non U.S.) slips over a tow-ball. Tow-balls come in various sizes depending on the load they carry and the country of operation:
*1 7/8 in (47.6 mm)
*50 mm (1.97 in) (ISO standard)
*2 in (50.1 mm)
*2 5/16 in (58.7 mm)
Outside the U.S. the vehicle mounting for the tow-ball is called the tow-bracket. The mounting points for all recent passenger vehicles are defined by the vehicle manufacturer and the tow-bracket manufacturer must use these mount points and prove the efficacy of their bracket for each vehicle by a full rig-based fatigue test.
In order to tow safely the correct combination of vehicle and trailer must be combined with correct loading horizontally and vertically on the tow-ball. Advice should be taken (see references) to avoid problems.
In North America the ball attaches to a ballmount. Receiver-type hitches use removable ball mounts, whereas the fixed drawbar type hitches have integrated ball mounts. The ballmount must match the US hitch class. The ballmount for a receiver-type hitch is a rectangular bar that fits into a receiver attached to the vehicle. Removable ball mounts are offered with varying rise or drop to accommodate variations in the height of the vehicle and trailer to provide for level towing.
European Union, towbars must be a type approved to European Union directive94/20/EC to be fitted to automobiles first registered on or after 1 August 1998.
The ISO standard tow-ball is 50mm in diameter and conforms to a standard BS AU 113b. The ISO standard has been adopted in most of the world outside North America.
There are two main categories of ISO tow-ball - the flange fitting and the swan-neck which has an extended neck fitting into the tow-bracket. Swan-neck tow-balls are often removable to avoid the inconvenience of a tow-ball protruding from the vehicle when not required. Some manufacturers are introducing retractable tow-balls as an option.
Across Europe around 25% of the vehicle park have tow-balls fitted - but there are distinct regional variations with Benelux and Scandinavia having 70 to 90% of vehicles with tow-balls.
Trailer Tow hitch
Cars can include trailer tow hitch with a removable tow ball.
Weight Distributing Hitch
A weight distributing hitch is a "load leveling" hitch. It is a hitch setup mounted on the tow vehicle that uses spring bars under tension to distribute part of the trailer's hitch weight from the towing vehicle's rear axle to the towing vehicle's front axle and to the trailer's axle(s). It can help reduce trailer sway and hop. Trailer hop can jerk the tow vehicle. Trailer sway is sometimes called "fish tailing". At high speeds, trailer sway can become dangerous. Most vehicle manufacturers will only allow a maximum trailer capacity of 5000 lbs. and 500 lbs. of tongue weight without using a weight distributing hitch. Tow vehicles often have square receiver sockets to accept weight distributing hitches.
A Lunette ring is a type of trailer hitch that works in combination with a
pintlehook on the tow vehicle. A pintle hook and lunette ring makes a more secure coupling, desirable on rough terrain, compared to ball-type trailer hitches.
* [http://www.towingguide.com/couplings.html Towing Guide - Couplings]
* [http://europa.eu.int/eur-lex/lex/LexUriServ/LexUriServ.do?uri=CELEX:31994L0020:EN:HTML Directive 94/20/EC of the European Parliament]
* [http://www.sizes.com/home/trailer_hitches.htm Trailer hitches]
* [http://www.ntta.co.uk/law/index.htm UK National Towing & Trailer Association]
* [http://www.hitchsource.com/hitch_guide.php Trailer Hitch Guide]
* [http://www.longhornsales.com/definitions.htm Longhorn Motors, Ltd.] Definitions of North American towing terms
Wikimedia Foundation. 2010.
Look at other dictionaries:
Hitch — may refer to* Hitch knot, a knot used to attach a rope to a fixed object. * Tow hitch, a construction on a truck or car to attach a trailer. * Hitches, fish in the genus Lavinia (genus) including Lavinia exilicauda * Hitch (film), a movie… … Wikipedia
Tow truck — Heavy Tow truck Wrecker on duty in Jyväskylä, Finlan … Wikipedia
tow —  To pull a trailer behind a vehicle by means of a towing hitch.  To pull a disabled vehicle behind another vehicle by means of a rope, cable or rigid bar … Dictionary of automotive terms
Trailer (vehicle) — A Trailer is generally an unpowered vehicle pulled by a powered vehicle. Commonly, the term trailer refers to such vehicles used for transport of goods and materials.Sometimes recreational vehicles, travel trailers, or mobile homes with limited… … Wikipedia
Towing — is the process of pulling or drawing behind a chain, line, bar or some other form of coupling. Commonly, towing is done by road vehicles, but anything from boats to tractors to people can tow cargo. Types of trailers Almost any SUV, van, minivan … Wikipedia
Travel trailer — A travel trailer or caravan is a trailer towed behind a road vehicle to provide a place to sleep which is more comfortable and protected than a tent (although there are fold down tent trailers). [ [http://www.gorving.ca/foldingcamping.asp Folding … Wikipedia
Motorcycle accessories — are features and accessories selected by a motorcycle owner to enhance safety, performance, or comfort, and may include anything from mobile electronics to sidecars and trailers. An accessory may be added at the factory by the original equipment… … Wikipedia
Ford Super Duty — See also Ford Super Duty engine for the 401, 477, and 534 engines built from 1958 to 1981. Infobox Automobile name = Ford Super Duty manufacturer = Ford Motor Company production = 1999 present predecessor = Ford F 250/350 class = Full size pickup … Wikipedia
U-Haul — Infobox Company company name = U Haul International, Inc. company company type = Public (NYSE|UHAL) slogan = Moving Families to Better Lives Since 1945. foundation = Ridgefield, Washington 1945 location = Phoenix, Arizona USA key people = Leonard … Wikipedia
Yard ramp — A yardramp, sometimes called mobile yardramp or container ramp, is a movable metal ramp for loading and unloading of shipping containers and vehicle trailers, without the need for permanent docking bays. A yardramp is placed at the back of a… … Wikipedia