Paccar Inc.

John C Lindsley

Huston R Marlowe

Alan Havassy

Huston Marlow

Truck cab roof

A truck tractor-trailer assembly having reduced aerodynamic drag. The skins of the tractor cab and trailer extend longitudinally toward each other and terminate in opposed trailing and leading edges which are as close together as possible while still permitting a full range of yaw and upward pitch about a fifth wheel assembly coupling the trailer to the tractor. In addition to accommodating yaw and upward pitch, the tractor-trailer skin edges are separated by a minimum clearance distance determined by manufacturing tolerances, plus clearances in the fifth wheel assembly, plus elastic deformation of components, plus the range of maximum roll of the tractor frame. An optimal construction employing concentric spherical surfaces is shown, as are embodiments having minimum skin and volume gaps meeting other design criteria. A method of reducing aerodynamic drag by reducing tractor-trailer skin and volume gaps also is described.

Tractor-trailer aerodynamic drag reduction apparatus and method

Truck cab

Truck roof fairing

Truck grill unit

Exterior shell of a truck cab body

A truck including a cab having a front windshield, opposite driver and passenger doors, a cab roof, and a roof fairing disengageably mounted to the cab roof is disclosed herein. The windshield, cab roof and roof fairing are configured so that they present a substantially smooth outer front and side joints between their adjacent outer surfaces, whereby to enhance the aerodynamic qualities of the cab. In the actual embodiment disclosed, the truck is of the conventional class 7 or 8 type as opposed to the cab-over-engine type of truck and is designed so that its opposite driver and passenger doors are located behind the driver and passenger seats rather than directly beside them. At the same time, both the truck's hood and its windshield wrap around the cab to points adjacent these mid-position doors. The hood is pivotally mounted to the cab and opens up and rearward.

Highway truck-tractor

Front panel for a truck

Growing community of inventors

Felton, CA, United States of America

John C Lindsley