GB2128950A

GB2128950A - An air deflector assembly for a motor vehicle

Info

Publication number: GB2128950A
Application number: GB08230412A
Authority: GB
Inventors: Robert Jeffery Evans
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-10-25
Filing date: 1982-10-25
Publication date: 1984-05-10

Abstract

The tractor of an articulated motor vehicle is provided with an air deflecting vane (6). The vane (6) is mounted pivotally on a frame (2) which is secured to the roof (4) of the tractor. A power-operated actuator (14) is provided to adjust the angle of inclination of the vane (6). The actuator may be controlled manually, for example by means of a rocker switch in the cab of the tractor, or automatically, for example in response to wind pressure downstream of the vane (6). In either case, the vane (6) may be adjusted during travel to obtain the optimum angle of inclination for prevailing conditions. <IMAGE>

Description

SPECIFICATION An air deflector assembly for a motor vehicle This invention relates to air deflectors for motor vehicles, and particularly, although not exclusively, to air deflectors for mounting on the cab of a commercial vehicle.

It is becoming increasingly common for such air deflectors to be mounted on the cabs of commerical vehicles. Such air deflectors modify the air flow around the moving vehicle and are intended to provide a smooth flow of air over the cab and over parts of the vehicle, or of a load carried by the vehicle, behind the cab. This reduces the drag coefficient of the vehicle as a whole and so reduces fuel consumption. The air deflectors are also intended to improve the handling characteristics of the vehicle.

Most deflectors which are in current use are rigidly secured to the cab roof and can not be adjusted to suit different weather and driving condtions nor to suit different load conditions.

For example, while an air deflector on the tractor of an articulated vehicle can provide benefits while the tractor is hauling a trailer of a particular height, it can worsen performance if the tractor is hauling an unloaded flatbed trailer or is being driven without any trailer at all. Furthermore, an air deflector significantly increases the height of the cab, and this can cause difficulties, for example when driving the vehicle into a workshop through a doorway of limited height.

The mounting of some air deflectors permits limited adjustment, but adjustment can only be carried out when the vehicle is stationary, because it is necessary for a fitter to climb on to the top of the vehicle and use tools to make the adjustment. This means that adjustment can usually be made only at the vehicle's home base, but it is not practical for the driver to make his own adjustments to suit varying conditions which may be encountered during the course of a journey.

According to the present invention there is provided an air deflector assembly for a motor vehicle, comprising a frame for mounting on the roof of a motor vehicle and a vane which is pivotally connected to the frame, a power operated actuator being provided for adjusting the angular position of the vane relative to the frame.

With such an assembly fitted to a cab, the driver of the vehicle can make adjustments to the angular position of the vane without requiring any tools. It is possible for adjustment to be made from within the cab, even while the vehicle is in motion, if control means, such as a rocker switch, is provided on the dashboard of the vehicle or at some other location convenient to the driver. By adjusting the vane while the vehicle is in motion, the driver can sense the ideal position for the deflector under differing prevailing conditions.

A gauge may also be provided on the dashboard to provide a remote indication of the angular position of the vane.

In a preferred embodiment, the actuator is an electromechanical linear actuator, although other types of actuator could be used, such as a hydraulic cylinder and piston unit. The actuator forms part of a linkage which enables the position of a strut to be modified so as to adjust the angle of the vane.

For most uses, it is sufficient for the vane to have a range of movement of between 0" and 60 relative to the cab roof. The vane is preferably shaped so that, when it is in its lowermost position, it covers and encloses at least part of the frame and the actuator.

Most truck cabs have gutters extending around at least the sides and rear of the cab, and preferably the frame is adapted to engage these gutters to secure the frame to the vehicle. The frame may be adjustable to fit different cabs. Where no such gutter is provided, the frame may be adapted to be riveted or otherwise secured directly to a suitably reinforced part of the cab roof.

For a better understanding of the present invention, and to show how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a side view of the top of the cab of a commercial vehicle fitted with an air deflector which is in a raised position; Figure 2 corresponds to Fig. 1 but shows the air deflector in a lowered position; Figure 3 is a plan view taken in the direction of the arrow Ill in Fig. 1; Figure 4 is a view corresponding to Fig. 1 but showing an alternative construction; and Figure 5 is a plan view taken in the direction of the arrow V in Fig. 4.

Referring first to Figs. 1 to 3, the air deflector assembly comprises a frame 2 which is secured to the roof 4 of the cab. A vane 6 is mounted on the frame 2 for pivotal movement about an axis near its leading edge. The angular position of the vane 6 relative to the frame 2 is maintained by two struts 8. Each strut 8 is pivotally connected at one end to the vane 6 and at the other end to a slider 10. As can be appreciated from Fig. 3, the struts extend in generally opposite directions from the slider 10 and terminate near the ends of the vane 6. The connection between the struts and the vane on the one hand and the slider on the other hand can be made by spherical ball joints to enable universal pivotal movement to take place.

The slider is mounted on two parallel members 1 2 of the frame 2. Mounted between the members 1 2 is an electro magnetic linear actuator 14 which includes an electric motor 1 6. The motor drives a screw threaded spin dle on which a nut connected to a plunger 1 8 cooperates so that rotation of the spindle causes the plunger to be extended from, or retracted into, the casing of the actuator. The plunger is connected to the slider 1 0.

The parallel frame members 1 2 are connected, for example by welding, to a crossmember 20 to which the vane 6 is pivotally connected. Towards each end of the crossmember 20 there is a gutter clamp 22. The frame members 1 2 are hollow and receive respective inner members 24 which are interconnected at their ends projecting from the members 1 2 by a plate 26 to which a further gutter clamp 28 is connected. The gutter clamps 22 and 28 engage a gutter 30 extending round the sides and rear of the cab 4.

The gutter clamps 22 can be displaced along the cross-member 20 to enable the frame 2 to be fitted to cabs of different widths. Similarly, the inner members 24 can be slid into and out of the members 1 2 to adjust the position of the gutter clamp 28. Locking means (not shown) is provided to lock the gutter clamps 22 and 28 in their adjusted positions. the locking means may, for example, comprise lock screws. By altering the positions of the gutter clamps, the frame can be adjusted to fit a wide variety of cabs, including so-called "sleeper" cabs which are extended to the rear to provide a sleeping area for the driver. This facility enables the assembly to be transferred without difficulty from one vehicle to another.

Although not shown in the drawings, electrical wiring extends from the motor 1 6 to a polarity change rocker switch mounted at a convenient position in the cab, for example on the dashboard. Also a gauge may be mounted in the cab for providing a visual indication of the angle of inclination of the vane 6. To provide a signal for the gauge, a potentiometer may be fitted to, for example, the cross member 20 with a wiper fixed to the vane 6.

It will be appreciated that the angle of incidence of the vane can be adjusted by the driver while the vehicle is in motion to provide an optimum setting. By way of example, assuming the air deflector assembly is fitted to a flat-bed truck, a typical journey may comprise the conveyance of a relatively high load, extending above the top of the cab 4, over a route which comprises some high speed motorway driving and some relatively slow driving. For these two types of driving, optimum performance may require different angles of inclination of the vane 6, and this can be achieved very simply by the driver, who would normally be able to sense when the vehicle is operating under optimum conditions, either from the way the vehicle is handling or by listening to the wind noise generated by air passing over the vehicle.For the return journey, the trailer may be empty, in which case the vane 6 may be lowered right down onto the roof of the cab 4.

Figs. 4 and 5 show an alternative form for the assembly. The frame comprises a front member 32, corresponding to the cross bar 20, a rear member 34 and two side members 36. Instead of the single rear gutter clamp 28, two rear gutter clamps 38 are provided, each mounted on an inner member 40 which is slidable into and out of the respective side member 36. As with the construction of Figs.

1 to 3, some form of locking means, such as a screw engaging a tapped hole in the tubular side members 36, is provided to retain the inner member 40 in a desired position.

The angular position of the vane 6 is maintained by two pairs of struts 42 and 44. One end of each strut 42 is connected pivotally to the vane, 6, and one end of the strut 44 is connected to the frame. The other ends of the struts of one pair are connected to the casing of the actuator 14 and those of the other pair are connected to the plunger 1 8.

As before, electrical wiring is provided which connects the actuator 1 4 to a rocker switch on the dashboard. Operation of the actuator 14 causes the struts 42 and 44 of each pair to pivot relatively to each other, so raising or lowering the vane 6.

Instead of being responsive to a driveroperated control, the actuator 1 4 may be controlled automatically. For example, a sensor may be mounted on the vehicle at a position behind the cab, for example on the front of a box body or a container on a trailer hauled by a tractor to whcih the air deflector assembly is fitted. The sensor may extend a small distance above the top of the container and may be divided into different pressuresensitive regions at different heights so that is provides an indication of the position at which air impinges on it. The sensor can then be connected to the actuator to control the actuator automatically to achieve a position in which the air flow over the cab is deflected by the vane 6 just over the top of the box body or the container.

It is also possible to control the actuator 14, when the air deflector assembly is mounted on a tractor of an articulated vehicle, so as to cause the vane 6 to fold flat automatically onto the roof of the tractor when a trailer is disconnected.

Claims

1. An air deflector assembly for a motor vehicle, comprising a frame for mounting on the roof of the vehicle and a vane which is pivotally connected to the frame, a poweroperated actuator being provided for adjusting the angular position of the vane relative to the frame.

2. An air deflector assembly as claimed in claim 1, in which the actuator is an electromagnetic linear actuator.

3. An air deflector assembly as claimed in claim 1, in which the actuator is a hydraulic cylinder and piston unit.

4. An air deflector assembly as claimed in any one of the preceding claims, in which the vane is supported by a rigid strut, one end of which is pivotally connected to the vane at a position away fom the axis of the pivotal connection between the vane and the frame, and the other end of which is connected to the actuator for displacement relative to the frame.

5. An air deflector assembly as claimed in claim 4, in which the strut is one of two similar struts, the said other ends of which are interconnected for movement together by the actuator.

6. An air deflector assembly as claimed in claim 5, in which the said other ends of the struts are pivotally connected to a common slider which is slidable along members of the frame.

7. An air deflector assembly as claimed in claim 4, in which the strut is one of two similar struts, the said other ends of which are connected respectively to two relatively displaceable parts of the actuator.

8. An air deflector assembly as claimed in claim 7, in which the two parts of the actuator are connected by respective further struts to the frame.

9. An air deflector assembly as claimed in any one of the preceding claims, in which control means is provided for operating the actuator.

10. An air deflector assembly as claimed in claim 9, in which the control means is manually actuable.

11. An air deflector assembly as claimed in claim 9 or 10, in which the control means is automatically actuable.

1 2. An air deflector assembly as claimed in claim 11, in which sensing means is provided for detecting wind pressure downstream of the vane, the control means being actuable automatically in response to signals generated by the sensing means.

1 3. An air deflector assembly as claimed in any one of the preceding claims, in which a gauge is provided for remotely indicating the angular position of the vane with respect to the frame.

14. An air deflector assembly as claimed in any one of the preceding claims, in which the vane is pivotable relatively to the frame through an angle of not less than 60 .

1 5. An air deflector assembly as claimed in any one of the preceding claims, in which the vane is movable into a position in which it covers and encloses at least part of the frame and the actuator.

1 6. An air deflector assembly substantially as described herein with reference to, and as shown in, the accompanying drawings.

1 7. A motor vehicle provided with an air deflector assembly in accordance with any one of the preceding claims.

1 8. A motor vehicle as claimed in claim 17, which is an articulated vehicle comprising a tractor and a trailer, the air deflector assembly being mounted on the tractor.

1 9. A motor vehicle as claimed in claim 1 8 when appendant to claim 11, in which the control means is adapted to move the vane into a lowermost position when the trailer is uncoupled from the tractor.

20. A motor vehicle as claimed in claim 1 8 or 1 9 when appendant to claim 12, in which the sensing means is mounted on the front of the trailer, or of a load carried by the trailer, and is responsive to wind pressure at different vertical levels, the control means being actuable automatically to adjust the vane to a position in which air flow over the tractor passes just over the top of the trailer or the load.

21. A motor vehicle substantially as described herein with reference to, and as shown in, the accompanying drawings.