GB2450114A

GB2450114A - Aerodynamic device for a vehicle

Info

Publication number: GB2450114A
Application number: GB0711353A
Authority: GB
Inventors: Adil Shazad; Faisal Siddiq
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-06-13
Filing date: 2007-06-13
Publication date: 2008-12-17
Also published as: GB0711353D0

Abstract

An aerodynamic device 2 for a vehicle comprises a body with a domed front surface 8 and a concave rear surface 10. An annular mounting surface 12 surrounds the rear surface 10.

Description

ENERGY SAVING DEVICE FOR VEHICLES

Background of the invention

The invention pertains to the field of improving the energy efficiency of motor vehicles such as automobiles, buses, trucks and motorcycles.

Vehicle designers generally take aerodynamic considerations into account and design vehicles to be as streamlined as possible in order to reduce fuel consumption. British patent application GB 2424396 A by the present inventors describes a simple, transparent dome-shaped plastic device that can be attached to a vehicle's front registration plate to reduce the air resistance offered by that planar surface. However, that does not exhaust the possibilities for modifying the external shape of a vehicle to improve its fuel efficiency.

Brief summary of the invention

The present invention provides an energy saving device for a vehicle as defined in claim 1.

It further provides A method of modifying the aerodynamic shape of a motor vehicle as defined in claim 6.

Preferred embodiments of the invention are defined in the subclaims.

Because the device is deformable, it can adapt to fit the profile of different curved surfaces on one vehicle or many vehicles. Thus it is not limited to use on planar surfaces such as a registration plate. It has been found that attaching the devices at other locations on a vehicle can effect worthwhile savings in fuel consumption, as discussed below.

Brief descriinion of the drawings Fig. 1 is a cross section through the centre of an energy saving device according to the invention against a planar surface.

Fig. 2 is a perspective view of the rear windscreen of a saloon car showing preferred positions for attaching the devices according to the invention.

Fig. 3 is a view similar to Fig. 2 showing alternative positions for attaching the devices according to the invention.

Fig. 4 is a view similar to Fig. 2 and Fig. 3 showing a preferred position for attaching a single device according to the invention.

Fig. 5 is a perspective view of the front of a car showing further preferred positions for attaching the devices according to the invention.

Detailed description of the invention

Fig. 1 is a cross section through the centre of an energy saving device 2 according to the invention in its relaxed state. For convenience, the device is shown attached to a fiat surface 4.. However, as discussed below, the device can also be deformed from its relaxed state so as to be attached to a gently curved surface of a vehicle such as a windscreen.

The device 2 has a circular rim 6 surrounding a domed front surface 8. The rear surface 10 is concave and typically -though not necessarily -follows the profile of the front surface 8 so that the device is of roughly uniform thickness. Surrounding the concave portion of the rear surface 10, between it and the rim 6, is an annular mounting surface 12, which is planar when the device 2 is in its relaxed state.

The domed front surface 8 of the device has a central area 9 with positive curvature, i.e. it is convex in all directions. Towards the rim 6, the front surface 8 flares outwards to form a region II of negative curvature, i.e. it is concavo-convex (concave as seen in the crosssection of Fig. I but convex as measured around the circumference). This helps to shed air from the device and avoid a sharp change in angle between the front surface 8 and the underlying surface 4 of the vehicle at the rim 6.

As previously mentioned, the device 2 is preferably made from a flexible plastic material so as to allow the mounting surface 12 to deform and adapt to the gently curved profile of the surface 4 of a motor vehicle. However, the device 2 should not be so flexible that it does not retain its overall domed and flared shape when in use.

Nor should it be applied to surfaces 4 that are so tightly curved that the device is under excessive strain and likely to spring free when in use.

It is preferred that the mounting surface 12 of the device be attached to the vehicle by double sided tape but other adhesives may be used, as is well known. Preferably, they should allow the device 2 to be removed from the vehicle in order to change its position or to remount it on another vehicle if desired.

The device is preferably made transparent so that the colour of vehicle body shows through it and the device appears unobtrusive. However, it may be coloured or patterned as desired, either by making it from a coloured material or by coating the front or rear surface, for example to match the vehicle colour or the black surround typical of a vehicle windscreen.

A preferred position for mounting the device is on the rear windscreen. As shown in Fig. 2, it has been found that the best option for a family saloon car is a pair of the devices mounted on the upper corners of the rear windscreen 14. This has been found to increase typical fuel economy by 2 to 3 miles per gallon (0.7 to 1.1 km/l). If the operation of rear windscreen wipers does not allow the devices to be placed in this way, they can be moved closer to the centre, as shown in Fig. 3, or a single device at the centre may be used as shown in Fig. 4, with a corresponding reduction in savings.

It is expected that for cars with gently sloping rear windscreens 14, it will be best to position the devices close to the upper edge of the screen as shown in Figs. 2 to 4.

For cars with more vertical rear windscreens, such as small hatchbacks, corresponding positions at the lower edge of the screen may be more efficient.

The devices can also be placed on the front corners of the car, as shown in Fig. 5. The headlight housings 16 provide a suitable curved surface on many cars. Naturally the devices must not obscure.the lights so they may placed in the corners of the housing, away from the lights or may be transparent, for example covering the indicator lights.

Claims

1. An energy saving device for a vehicle, comprising: a body having a domed front face, a concave rear face and a rearwardly-facing, annular mounting surface surrounding the rear face; wherein the body is deformable from its relaxed state so that the mounting surface can lie flush against a curved surface of a vehicle.

2. An energy saving device according to claim 1, wherein in the relaxed state of the device the annular mounting surface is generally circular.

3. An energy saving device according to claim 2, wherein in the relaxed state of the device the ratio of the height to the diameter of the device is less than 1:5.

4. An energy saving device according to any preceding claim, wherein in the relaxed state of the device the mounting surface is generally planar.

5. An energy saving device according to any preceding claim, wherein in the relaxed state of the device the domed front face has a central region of positive curvature and flares outwards to form a region of zero or negative curvature close to thenm.

6. A method of modifying the aerodynamic shape of a motor vehicle comprising the step of attaching to each of at least one curved surface of said vehicle a device having a domed front face, a concave rear face and a rearwardly-facing, annular mounting surface surrounding the rear face; wherein the step of attaching the body includes deforming the device from its relaxed state so that the mounting surface lies flush against the curved surface of a vehicle.

7. A method according to claim 6, comprising attaching a pair of the devices to generally forwardly-facing curved surfaces at two front corners on either side of the vehicle.

* . -6-

8. A method according to claim 6, comprising attaching at least one of the devices to a rear windscreen of the vehicle.

9. A method according to claim 8, comprising attaching a pair of the devices respectively to two upper corners of the rear windscreen.

10. A method according to claim 8, comprising attaching a pair of the devices respectively to two lower corners of the rear windscreen.

11. A method according to claim 8, comprising attaching one or a pair of the devices close to the centre of an upper edge of the rear windscreen.

12. An energy saving device for a vehicle substantially as described herein with reference to the drawings.