What is a Fifth-Wheel? Originally, a fifth wheel was a steering mechanism resembling a wheel that enabled the front axle of a horse-drawn wagon to rotate when making turns. This coupling scheme required three men to hook to and unhook the trailer from the automobile. The new fifth wheel design used a jaw with a spring locking device mounted on the fifth wheel plate that was attached to the tractor frame. Today, the fifth wheel serves as a coupling device that attaches a road tractor to a semi-trailer. A fifth wheel is a heavy metal disc with a "V" shaped slot. It is attached horizontally to the chassis above the rear axles of the road tractor. A kingpin is a heavy metal cylindrical pin that is located underneath the front end of the trailer. The kingpin is the mechanism on the trailer that locks it to a road tractor. It is typically positioned between 18" to 48" from the trailer nose. A greased metal grid plate surrounds the kingpin. This grid plate allows the fifth wheel to slide underneath the trailer. When the tractor is backed into the nose of a trailer, the fifth wheel pivots and slides underneath the trailer's grid plate. The fifth wheel then locks onto the trailer's king pin.

You can use Chassis Semi Trailer if you need to transport your vehicle from one place to another or when relocating to a new place. The Chassis Semi Trailer is ideal when your cargo can withstand the various elements like rain, wind etc. They can easily hold up to eight or ten cars.  On the other hand, you can go for enclosed trailers which are more expensive than the open ones, but your goods will be far safer. For more information about Chassis Semi Trailer, see Xiamen Wondee Autoparts Co., Ltd. .

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