GB2136362A

GB2136362A - Aerodynamic Deflector for Vehicle Roof

Info

Publication number: GB2136362A
Application number: GB08306522A
Authority: GB
Inventors: Keith R Hemmimgs; Martin J Fletcher
Original assignee: Leyland Vehicles Ltd
Current assignee: Leyland Vehicles Ltd
Priority date: 1983-03-09
Filing date: 1983-03-09
Publication date: 1984-09-19
Also published as: GB8306522D0

Abstract

A wedge-shaped hollow canopy (1) is mounted as an aerodynamic deflector and sun shield over the cab roof of a commercial vehicle to control the air flow (4) over loads of variable height. The canopy is hinged (3) at its front edge to the cab roof and is supported at any desired angle (5) by a pair of hydraulic struts (2), controlled at ground level by pumps (6). The space under the canopy is usable as cab accommodation, since the cab roof projects into the canopy shell. <IMAGE>

Description

SPECIFICATION Aerodynamic Deflector for Vehicle Roof This invention relates to deflectors for attachment to vehicle roofs and is particularly useful for driver's cabs on large commercial vehicles where it is desirable to control the aerodynamic flow between the cab roof and the load.

The invention consists in an aerodynamic deflector for mounting over a cab or other vehicle roof, comprising: a canopy with a roof and two side walls broadly defining a wedge-shaped shell, of which a thin end is adapted to be hinged to the roof to constrain the canopy to pivotal motion in a vertical plane; and means for positioning and holding the canopy at a selected vertical angle such that the canopy roof presents a suitably angled aerodynamic deflecting surface above the cab or other roof; the canopy being shaped partially to enclose the cab or other roof at least when held in its lowest angular position.

The invention also consists in a vehicle having a roof and an aerodynamic deflector mounted over the roof, the deflector comprising a canopy with a roof and two side walls broadly defining a wedge-shaped shell, whose horizontal thin end is hinged to the front of the vehicle roof constraining the canopy to pivotal motion in a vertical plane; and means for positioning the canopy at a vertical angle such that the canopy roof presents a suitable aerodynamic deflecting surface; the canopy being shaped partially to enclose the vehicle roof at least when in its lowest angular position; and the vehicle comprising means remote from the canopy co-operating with the positioning means for adjusting the said vertical angle.

In the preferred form of the invention, the canopy is positioned at its selected vertical angle by means of one or more hydraulic struts between the rear of the canopy and the rear of the vehicle roof, the length of the struts being adjustable remotely by pumping associated hydraulic pumps.

The preferred shape of canopy, suitable for a dome-shaped driver's cab roof, broadly follows the outer shape of the roof, and has a roof portion, two broadly triangular upright side walls and an upright rear wall, the canopy becoming progressively shallower towards the front edge which is hinged to the cab roof.

To strengthen the mounting of the deflector canopy, a lateral suspension may connect the vehicle roof to the inside of the canopy, and a tubular Panhard rod is suitable for this purpose.

The canopy may have a raised front portion with a grille for an air-conditioning air intake, communicating with a portion of the vehicle roof below.

The advantages of the invention include the ability to adjust the deflector angle, remotely from the roof at ground level, to suit the height or shape of any load carried by the vehicle behind the vehicle roof. The space under the deflector is used for accommodation, because the vehicle roof projects into the shell of the canopy. The deflector may also act as a sun shield, providing extra insulation from the effect of the sun, especially useful in hot climates.

In order that the invention may be better understood, a preferred embodiment will now be described with reference to the accompanying drawings, wherein: Figure 1 is a sketch of the front part of an articulated truck, showing the driver's cab with an aerodynamic deflector embodying the invention: Figure 2 illustrates in plan view the adaptation of a conventional flat cab roof to form the preferred type of raised roof suitable for receiving a deflector according to the preferred embodiment; Figure 3 illustrates, as a perspective view from the front, the modified raised cab roof, the base of which is shown in Figure 2; Figure 4 is a perspective view from the front of the complete cab roof of Figure 3 with the deflector over it, according to the preferred embodiment; and Figure 5 is a perspective view from the rear of the complete cab roof and deflector of Figure 4.

Figure 1 shows a tractor pulling a load attached to its chassis through a fifth-wheel turntable. There is a substantial gap between the driver's cab and the load, and the aerodynamic characteristics of the cab roof are important in determining the smooth flow 4 of air over and around the load. A deflector 1, pivotably mounted at the front of the cab roof by hinges 3 for motion 5 in a vertical plane, presents an inclined, smooth surface at the top of the cab. The angular position of the deflector 1 is held by a pair of hydraulic struts 2, whose lengths are independently adjustable by hydraulic pumps 6 connected to their respective struts and operable remotely, at ground level.

The space within the shell of the deflector canopy 1, which is wedge-shaped with the thin end of the wedge at the front of the vehicle, is utilised by raising the cab roof, thus creating further accommodation within the cabin, for example for a top bunk in a sleeper cabin. The cab roof, which is a rigid, sealed structure underlying the deflector canopy, is shown most clearly in Figure 3. Figure 2 illustrates a stage in the process of adapting a conventional flat cab roof to form the raised cab roof of Figure 3. The flat roof 7, with standard stiffeners and light mountings, is adapted by cutting out portions 8 and 9 and flanging out the edges. A fibre-glass moulding, consisting of three pieces 15, 1 6, 1 7, is then mounted on the flanges, and an air conditioner air intake 19, with a fan, is mounted over portion 9.A tubular support 14 holds the raised portion 15, 16, 17, 19 onto the remainder 7 of the roof, with weather seals throughout. Air-conditioner air pipes 18 convey air from the intake 19. A pair of hydraulic struts 2 is mounted in readiness for the deflector, as are the pair of hinges 3 at the front. A tubular Panhard rod 12 is joined at one end 13 to the tubular support 14 and at the other end to the inside of the deflector, when in position, to provide lateral support.

The deflector canopy, mounted over the cab roof, is shown from the front and rear in Figures 4 and 5 respectively, in the raised position, the struts 2 fully extended. An air intake 11 communicates with the cab roof air intake 19, and a pair of marker lights 10 are positioned over the hinges. Extraction slots 20 are formed in an upright rear wall of the deflector canopy 1, as shown in Figure 5.

In the preferred construction, the struts may extend by as much as 400 mm from the lowest to the fully raised angular position of the deflector, the angular range being about 20 degrees. This range is intended to provide suitable aerodynamic deflection for a wide range of heights of the load carried behind the cab for example the range 3.7 m to 4.2 m. The deflector also doubles as a sun shield, or adjustable "sun visor".

The invention has been described in its application to one design for a truck, but alternative designs are envisaged. Instead of the hydraulic pumps, operated at ground level, the hydraulic struts could be operated automatically, for example from a vehicle hydraulic circuit, by control from the cab or elsewhere. The hydraulic struts could be replaced by an electrically driven lift, for example using a worm-drive motor. The particular design of deflector is dictated partly by the services to be housed by it for example an airconditioning unit, but any suitable shell-like structure pivoted at the front is applicable.

Claims

1. An aerodynamic deflector for mounting over a cab or other vehicle roof, comprising: a canopy with a roof and two side walls broadly defining a wedge-shaped shell, of which a thin end is adapted to be hinged to the roof to constrain the canopy to pivotal motion in a vertical plane; and means for positioning and holding the canopy at a selected vertical angle such that the canopy roof presents a suitably angled aerodynamic deflecting surface above the cab or other roof; the canopy being shaped partially to enclose the cab or other roof at least when in its lowest angular position.

2. A vehicle having a roof and an aerodynamic deflector mounted over the roof, the deflector comprising a canopy with a roof and two side walls broadly defining a wedge-shaped shell, whose horizontal thin end is hinged to the front of the vehicle roof constraining the canopy to pivotal motion in a vertical plane; and means for positioning the canopy at a vertical angle such that the canopy roof presents a suitable aerodynamic deflecting surface; the canopy being shaped partially to enclose the vehicle roof at least when in its lowest angular position; and the vehicle comprising means remote from the canopy co-operating with the positioning means for adjusting the said vertical angle.

3. A vehicle in accordance with claim 2, wherein the canopy is positioned at its selected vertical angle by means of one or more hydraulic struts between the rear of the canopy and the rear of the vehicle roof, the length of the struts being adjustable remotely by a pump or pumps connected to the struts.

4. A vehicle in accordance with claim 2 or 3, wherein the interior shape of the canopy broadly follows the exterior shape of the top portion of the vehicle roof, and wherein in the lowest angular position of the deflector a substantial proportion of the interior volume of the canopy is usable as accommodation space within the vehicle.

5. A deflector or a vehicle with a deflector, in accordance with any preceding claim, wherein the canopy has a roof portion, two broadly triangular upright side walls and an upright rear wall, thus defining a triangular wedge-shaped shell, open at one face.

6. A vehicle in accordance with claim 2, 3, 4 or 5, wherein a lateral suspension connects the interior of the canopy to the vehicle roof in order to resist lateral force on the deflector.

7. An aerodynamic deflector, or a vehicle having an aerodynamic deflector, substantially as described herein with reference to the accompanying drawings.