GB2233843A

GB2233843A - Deceleration responsive vehicle brake light system

Info

Publication number: GB2233843A
Application number: GB9011051A
Authority: GB
Inventors: Ian James Thompson
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-05-17
Filing date: 1990-05-17
Publication date: 1991-01-16
Anticipated expiration: 2010-05-17
Also published as: GB2233843B; GB8911272D0; GB9011051D0

Abstract

A vehicle brake light system has brake light means adapted to be illuminated on actuation of a brake pedal, and sensor means for sensing the deceleration of the vehicle, with the sensor means being able to initiate illumination of the brake light means at a predetermined level of deceleration of the vehicle, independently of the actuation of the pedal. The brake light means will therefore indicate vehicle deceleration, even though the pedal is not actuated. The sensor means may also be used to control variation in the intensity and/or illuminable area of the brake light means in order to indicate variation in vehicle deceleration. The sensor may be disabled when the vehicle is travelling backwards.

Description

VEHICLE BRAKE LIGHTS This invention relates to vehicle brake lights.

Currently, vehicle brake lights simply indicate the fact that the brake pedal has been actuated, and do not indicate the rate of deceleration of the vehicle.

This has the disadvantage that it is difficult for a driver of a vehicle to tell how hard the vehicle in front is braking, and this often leads to accidents.

There have been proposals for indicating variation in deceleration by varying the intensity or area of the brake lights, in response to excessive deceleration or brake pressure, but these systems operate only when the brake pedal has been actuated, and not in any other circumstances to indicate excessive deceleration.

According to the present invention, a vehicle brake light system includes a vehicle brake light means adapted to be illuminated on actuation of a brake pedal, and sensor means for sensing the deceleration of the vehicle, the sensor means being operative to control initial illumination of the brake light means at a predetermined level of deceleration of the vehicle, independently of the actuation of the brake pedal.

Thus, in this system deceleration of the vehicle above the predetermined level will be indicated by the brake light means, even though the brake pedal is not actuated.

The sensor means preferably comprises an inertia-operated sensor, whose output is used to control the vehicle brake light means. Conveniently the sensor is electro-mechanical. The system may also include means for disabling the sensor means when the vehicle is travelling backwards.

The vehicle brake light means may have variable intensity and/or illuminable area, with the sensor means being operative to control the intensity and/or illuminable area in proportion to the deceleration of the vehicle.

The variation in intensity or area in accordance with the vehicle deceleration indicates the amount of deceleration to drivers of following vehicles. The sensor means operates in this way whether initial illumination of the brake light means is controlled by the brake pedal or by the sensor means itself.

Where the intensity of the brake light means is variable, at least three levels of intensity are provided over the range of deceleration detected by the sensor means. Where the illuminable area is variable, it is increased at least twice over the range of deceleration, but without decreasing the intensity.

Preferably a brake light means replaces each of the standard brake lights provided on a vehicle. For variable intensity, each brake light means may comprise a single lamp of continuously variable intensity, located behind a light-transmitting lens means.

Instead of a single variable intensity lamp, at least three fixed intensity lamps may be used, the lamps being arranged such that the intensity increases as they are lit in succession. The lamps may be of different intensities.

For variable area, each brake light means comprises at least three lamps located behind a light-transmitting lens means and lit in succession.

The lamps may be of the same intensity, or increase in intensity with increasing deceleration.

Various embodiments of the invention are envisaged, and will now be described in more detail.

In a first embodiment a vehicle brake light system has a pair of vehicle brake light means, which replace the normal pair of vehicle brake lights, and so are adapted to be illuminated on actuation of a brake pedal, together with sensor means for sensing the deceleration of the vehicle and controlling the operation of the brake light means. The sensor means controls initial illumination of the brake light means at a predetermined level of deceleration, independently of actuation of the pedal, and subsequently controls illumination in accordance with vehicle deceleration.

Each brake light means comprises a single lamp located behind a light-transmitting lens, and variable in intensity in accordance with the current supplied to it. On initial illumination, whether by actuation of the brake pedal or operation of the sensor means, a first threshold value of current is supplied; the supply of current above the first threshold and up to a second threshold value is then controlled by the sensor means. The sensor means is of the inertia-operated electro-mechanical type, located at a suitable point on the vehicle body. It comprises a member which can travel freely within a housing in accordance with the deceleration of the vehicle, movement of the member creating an electrical output signal to indicate the deceleration.The output signal is used to control the amount of current supplied to the lamp, so that its intensity varies continuously, between the two threshold values, in accordance with the deceleration of the vehicle, in order to indicate the variation in deceleration.

In a modification, the single lamp is replaced by three or more fixed intensity lamps, all located behind the lens. A first lamp is adapted to be illuminated on actuation of the brake pedal or operation of the sensor means, and the output signal from the sensor is adapted to illuminate the remainder in succession, as threshold levels of deceleration are reached. Again, the intensity of the brake light means varies in accordance with the deceleration, but in discrete steps rather than continuously. The lamps may have the same or differing intensities.

In a further modification each brake light means comprises three fixed intensity lamps located behind a light-transmitting lens, with each adapted to illuminate a separate area of the lens, the arrangement being such that the illuminated area of the lens varies between a minimum and a maximum as the deceleration varies. A first lamp is adapted to be lit on actuation of the brake pedal or operation of the sensor means, to provide the minimum area, and the second and third lamps are lit in succession, under the control of the sensor means, as threshold levels of deceleration are reached, to give the maximum area. The output signal from the sensor means is adapted to light the second and third lamps as the threshold levels are reached.

The intensity of the second and third lamps is chosen so that the overall intensity of the brake light means is not reduced as the area of illumination increases to indicate the varying deceleration of the vehicle.

In yet another modification, four or more lamps may be used. In a further modification, the intensity of the second and subsequent lamps is chosen so that the intensity of the illuminated area increases as these lamps are lit.

In all the embodiments described above, disabling means may be included in the system to disable the sensor means or its output when the vehicle is travelling backwards. The disabling means may comprise a switch provided on the gear lever, the switch operating automatically when the vehicle is put into reverse gear.

Furthermore, the sensor means may be of any suitable inertia-operated type, not only electro-mechanical.

In all the embodiments described above, the brake light means may be provided in addition to the normal brake lights, instead of replacing them. In this case only one brake light means may be provided.

The invention has the advantage that, in addition to providing indication of the rate of deceleration of the vehicle by varying the intensity or area of the brake light means, deceleration of the vehicle above a predetermined level is indicated by illumination of the brake light means, even though the brake pedal is not actuated.

Claims

1. A vehicle brake light system including a vehicle brake light means adapted to be illuminated on actuation of a brake pedal, and sensor means for sensing the deceleration of the vehicle, the sensor means being operative to control initial illumination of the brake light means at a predetermined level of deceleration of the vehicle, independently of the actuation of the brake pedal.

2. A vehicle brake light system as claimed in claim 1, in which the sensor means comprises an inertia-operated sensor, whose output is used to control the brake light means.

3. A vehicle brake light system as claimed in claim 2, in which the sensor is electro-mechanical.

4. A vehicle brake light system as claimed in any preceding claim, in which the system includes means for disabling the sensor means when the vehicle is travelling backwards.

5. A vehicle brake light system as claimed in any preceding claim, in which the vehicle brake light means has variable intensity and/or illuminable area, the sensor means also being operative to control the intensity and/or illuminable area in proportion to the deceleration of the vehicle.

6. A vehicle brake light system as claimed in claim 5, in which at least three levels of intensity are provided over the range of deceleration detected by the sensor means.

7. A vehicle brake light system as claimed in claim 5, in which the illuminated area is increased at least twice over the range of deceleration detected by the sensor means, without decreasing the intensity of the brake light means.

8. A vehicle brake light system as claimed in claim 1, and substantially as described in any of the embodiments described herein.