Abstract: 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.

Abstract: A truck of the cab-over-engine type is disclosed herein and includes a cab mounted over the truck engine and many of the engine's cooperating components for pivotal movement between an upstanding, operating position and a titled, maintenance position. The truck also includes a frontal nose hood mounted to and in front of the cab for its own pivotal movement between a closed, generally vertical operating position and a tilted, open position for gaining access to certain ones of the components cooperating with the engine. A front bumper assembly is provided in front of the nose hood and includes a first bumper arrangement connected for pivotal movement with and forming part of the frontal nose hood and a second bumper arrangement maintained in a fixed position and unconnected with the first bumper arrangement, whereby when the frontal nose hood and first bumper arrangement are pivoted to an open position, the second bumper arrangement remains in a fixed position.

Abstract: A truck including a cab having a front windshield and opposite driver and passenger doors, for example a cab-over engine type of truck, is disclosed herein. This truck includes a cab roof, a roof fairing disengageably mounted on the cab roof, and a sunvisor disengageably connected to the cab roof in front of and below the roof fairing. All three of these components of the truck cab are configured so that they present substantially smooth outer front and side joints between adjacent outer surfaces of adjacent components, whereby to enhance the aerodynamic qualities of the cab.

Abstract: 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.

Abstract: A truck of the cab-over-engine type is disclosed herein and includes a cab which has a front windshield and opposite side doors and which is mounted over the truck's engine and many of the engine's cooperating components including its radiator for pivotal movement between an upstanding operating position and a tilted maintenance position. The truck also includes a frontal nose hood which carries a grille, front bumper and headlights and which is mounted to the cab in front of the radiator and forward of the front windshield for pivotal movement between a closed, generally vertical operating position in front of the radiator and a tilted open position.