Patent ID: 6554310
Filing Date: 2003-04-29
Classification: B62D

Abstract:
A fifth wheel adapted to be mounted on a tractor for releasable engagement with a kingpin carried by a trailer, comprising a mounting structure adapted to be securely mounted to the tractor, a fifth wheel plate mounted to said mounting structure and having a catch adapted to releasably engage the kingpin, said fifth wheel plate having a top bearing surface adapted to support a bottom bearing surface of the trailer when the kingpin is captively engaged with said catch, wherein said top bearing surface is rotatable with respect to said mounting structure for movement about an axis normal to said top bearing surface in response to an action exerted thereon by the bottom bearing surface of the trailer when the tractor turns relative to the trailer, and wherein said mounting structure includes a ramp adapted to provide support for the trailer while the same is being coupled to or uncoupled from the tractor, said fifth wheel plate being swingable between a lowered position wherein said top bearing surface is substantially at a lower elevation than said ramp and extends rearwardly downwardly at a given angle for allowing the kingpin to be engaged with or disengaged from said catch, and a raised position wherein said top bearing surface is located at a higher elevation than said ramp to support the trailer once the same has been coupled to the tractor, said ramp allowing said fifth wheel plate to be lifted as well as being pivoted forwardly under the action of the kingpin while the tractor is being moved backward towards the trailer.