The intention of a trailer coupler is to secure the trailer to the towing vehicle. It is an important piece, as the trailer couple attaches to the trailer ball. This then forms a ball and socket connection.It allows for relative movement between the towing vehicle and trailer while towing over uneven road surfaces. The trailer ball shouldbe mountedto the rear bumper or to a drawbar, which may be removable. The drawbar secures to the trailer hitch by inserting it into the hitch receiver and pinning it.
The three most common types of couplers used are straight couplers, A-frame couplers, and adjustable couplers.Another option is bumper-pull hitches in which case draw bars can exert a large amount of leverage on the tow vehicle.This makes it harder to recover from a swerving situation (thus it may not be the safest choice depending on your trip).
Trucks of the era mostly used two-cylinder engines and had a carrying capacity of 1,500 to 2,000 kilograms (3,300 to 4,400 lb). In 1904, 700 heavy trucks were built in the United States, 1000 in 1907, 6000 in 1910, and 25000 in 1914. A Benz truck modified by Netphener company (1895)
Aproperlyfitted close-coupled traileris fittedwith a rigid tow bar. It then projects from its front and hooks onto a hook on the tractor. It is important to not that it does not pivot as adraw bardoes.
The term 'trailer' iscommonlyusedinterchangeablywith that of a travel trailer or mobile home. There are varieties of trailers and manufactures housing designed for human habitation.Such origins canbe foundhistoricallywith utility trailers built in a similar fashion to horse-drawn wagons. A trailer park is an area where mobile homesare designatedfor people to live in.
In the United States, trailers ranging in size from single-axle dollies to 6-axle, 13 ft 6 in (4,115 mm) high, 53 ft (16,154 mm) in long semi-trailers is common.Although, when towed as part of a tractor-trailer or "18-wheeler", carries a large percentage of the freight.Specifically, the freight that travels over land in North America.
With the ending of World War I, several developmentswere madeto enhance trucks.Such an example would be by putting pneumatic tires replaced thepreviouslycommon full rubber versions.These advancements continued, including electric starters, power brakes, 4, 6, and 8 cylinder engines. Closed cabs and electric lighting followed. The modern semi-trailer truck also debuted.Additionally, touring car builders such as Ford and Renault entered the heavy truck market.