GB2280070A

GB2280070A - A brake light system

Info

Publication number: GB2280070A
Application number: GB9314069A
Authority: GB
Inventors: Gary Francis Kinsey
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-07-08
Filing date: 1993-07-08
Publication date: 1995-01-18
Also published as: GB9314069D0

Abstract

A vehicle brake light system comprises one or more supplementary brake lights 22, a source of electrical current 16 and a deceleration sensor 24, configured to initiate the passage of current to illuminate the supplementary brake lights only upon detection of a rate of deceleration greater than a predetermined value. Such an arrangement gives the driver of a following vehicle visual warning of heavy or emergency braking which he would not receive from the standard brake lights 14 this system supplements. Lights 22 may be energised via a flasher 42. A relay arrangement A, or an integrated circuit, may be incorporated so that lights 22 keep flashing, once activated by sensor 24, until the normal brake light switch 18 opens. The sensor 24 may be responsive to pressure in the braking system hydraulic circuit, or may be an inertia sensor such as a mercury switch. <IMAGE>

Description

A BRAKE LIGHT SYSTEM The present invention relates to a brake light system and relates particularly, but not exclusively, to a supplementary brake light system for a vehicle.

Conventional brake light systems employ a sensor which detects the initiation of braking by, for example, detecting an increase in the pressure of the hydraulic brake fluid or brake cable movement and then allows electrical current to pass to a brake light thereby to illuminate it. Such an arrangement, whilst providing an adequate indication that the vehicle brakes have been applied, is unable to indicate how rapidly the vehicle is decelerating.

It has been observed that drivers of following vehicles can, under certain circumstances, such as heavy rain or snow for example, where driver vision is impaired find it difficult to judge how heavily they should brake in order to avoid colliding with the vehicle in-front. Clearly, if the following driver fails to brake hard enough, he will collide with the vehicle in front whilst, if he brakes too hard, he could cause a following driver to collide with his vehicle. These problems are exacerbated when the driver of a following vehicle is distracted or is tired.

There is therefore a requirement for a vehicle brake light system which not only indicates that the brakes have been applied but also gives some indication of how rapidly the vehicle is decelerating.

It is an object of the present invention to provide a brake light system which reduces and possibly eliminates the above mentioned problem.

According to the present invention there is provided a vehicle brake light system comprising a supplementary brake light, a vehicle deceleration sensor and a source of electrical current connected to said brake light via said vehicle deceleration sensor and in which the deceleration sensor is configured to allow the passage of current to illuminate said supplementary brake light only upon detection of a rate of deceleration greater than a predetermined rate.

It will be appreciated that by providing a plurality of supplementary brake lights actuatable only upon detection of a deceleration rate greater than a predetermined value it will be possible to indicate not only that the vehicle is slowing down but that it is slowing down at a rapid rate.

Consequently, drivers of following vehicles will be able to act accordingly and avoid a collision.

In order to increase the visual effect, the supplementary brake light may be of a higher lighting intensity than any vehicle light it supplements.

For a further visual effect, there may be provided a circuit interrupter for momentarily and periodically interrupting the supply of current to the supplementary brake light so as to cause said supplementary brake light to flash on and off.

The deceleration sensor may comprise a mercury switch, a pressure sensor connected to the hydraulic braking current of said vehicle and operable to allow the passage of current upon detection of a predetermined fluid pressure corresponding to said predetermined deceleration rate, or an inertia sensor.

In order to increase the visual impact still further, the deceleration sensor may be configured to maintain the flow of electrical current to the supplementary brake light until braking ceases.

For convenience, the source of electrical current may comprise the vehicles standard electrical circuit.

Two or more supplementary brake lights may be provided.

The present invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a side view of a vehicle incorporating a brake light system according to the present invention, and Figure 2 is a circuit layout illustrating the various features of the brake light system incorporated in the vehicle illustrated in Figure 1.

Referring now to the drawings in general, a vehicle 10 includes a brake light circuit 12 best seen in Figure 2. The circuit 12 comprises one or more brake light 14 of standard intensity connected to a source of electrical current 16 via a brake light switch 18. Switch 18 is of a standard form and is generally activated by brake pedal movement or a rise in brake fluid pressure. In operation, electrical current is passed to the brake lights 14 thereby to illuminate them whenever and so long as the brakes are applied.

The present invention provides what is essentially a supplementary brake system 20 which includes one or more supplementary brake lights 22 connected to the vehicles source of electrical current 16 via a deceleration sensor 24. The deceleration sensor 24 is essentially a deceleration rate sensitive switch which is configured to pass current only upon detection of a deceleration rate greater than a predetermined rate.

The predetermined rate may be varied depending upon the safety factor required but is generally set at a rate corresponding to heavy or emergency braking.

A simple form of deceleration sensor 24 would comprise a mercury switch mounted in the vehicle in such a manner as to be operable only upon initiation of a rate of deceleration corresponding to heavy or emergency braking.

Alternatively, the deceleration sensor 24 may comprise a pressure sensor connected to the hydraulic braking circuit (not shown) on the vehicle and operable to allow the passage of current upon detection of a fluid pressure greater than a fluid pressure corresponding to said predetermined deceleration rate.

A relay system 30 best seen in box A of Figure 2 may be provided for enabling the supplementary brake lights to remain illuminated after the vehicle deceleration rate has fallen below said predetermined deceleration rate. The relay system comprises an actuator 32 connected at a first end to the source of electrical current via said deceleration sensor 24 and at its other end to earth. The actuator 32 is operably connected to two switches 34, 36 for simultaneous operation thereof. The first switch 34 acts to connect the first side of the actuator 32 to the source of electrical current 16 via standard brake light switch 18. The second switch 36 acts to connect the supplementary brake lights 22 directly to the source of electrical current 16. Alternatively, the relay system could be replaced by a simple integrated circuit chip programmed to perform the required functions.The design of such a chip does not form part of the present invention but the required features thereof will readily present themselves to a person skilled in electronic engineering.

In operation, actuator 32 is actuated only upon the closure of switch 24, i.e. upon detection of a heavy or emergency braking. Actuation of actuator 32 causes both switches 34, 36 to close thereby causing electrical current to flow via line 38 to supplementary brake lights 22 and via line 40 to the first side of actuator 32 where it supplements the current flowing via switch 24. Once the vehicle deceleration rate falls below the predetermined rate deceleration rate sensor 24 is deactivated causing a loss of current flow via itself to actuator 32. Standard brake switch 18 remains closed whilst the vehicle is still decelerating thus allowing current to be supplied to the actuator via line 40 until braking ceases.

As long as actuator 32 is supplied with current it will maintain switches 34 and 36 closed thereby ensuring the supplementary brake lights 22 remain illuminated until braking ceases. As soon as braking ceases switch 18 opens and cuts the supply of current to actuator 32 which is then unable to maintain switches 34, 36 in their closed position and hence supplementary brake lights 22 are turned off.

A circuit interrupter shown schematically at 42 may be provided for momentarily and periodically interrupting the supply of current to the supplementary brake lights 22 so as to cause said lights to flash on and off, thereby increasing the visual impact thereof. To further increase the visual impact, the supplementary brake lights may be of a higher intensity than the vehicle brake lights 14 that they supplement.

Claims

1. A vehicle brake light system comprising a supplementary brake light, a vehicle deceleration sensor and a source of electrical current connected to said brake light via said vehicle deceleration sensor and in which the deceleration sensor is configured to allow the passage of current to illuminate said supplementary brake light only upon detection of a rate of deceleration greater than a predetermined rate.

2. A vehicle brake light system as claimed in Claim 1 in which the supplementary brake light is of a higher lighting intensity than any vehicle brake lights it supplements.

3. A vehicle brake light system as claimed in Claim 1 or Claim 2 further including a circuit interrupter for momentarily and periodically interrupting the supply of current to the supplementary brake light so as to cause said supplementary brake light to flash on and off.

4. A vehicle brake light system as claimed in any of of Claims 1 to 3 in which said deceleration sensor comprises a mercury switch.

5. A vehicle brake light system as claimed in any one of Claims 1 to 3 in which said deceleration sensor comprises a pressure sensor connected to the hydraulic braking circuit of said vehicle and operable to allow the passage of current upon detection of a fluid pressure greater than a fluid pressure corresponding to said predetermined deceleration rate.

6. A vehicle brake light system as claimed in any one of Claims 1 to 3 in which the deceleration sensor comprises an inertia sensor.

7. A vehicle brake light system as claimed in any one of Claims 1 to 6 in which said deceleration sensor is configured to maintain the flow of electrical current to the supplementary brake light until braking ceases.

8. A vehicle brake light system as claimed in any one of the preceding claims in which the source of electrical current comprises the vehicles standard electrical circuit.

9. A vehicle brake light system as claimed in any one of the preceding claims in which there are two or more supplementary brake lights.

10. A vehicle brake light system substantially as herein described and as illustrated in Figures 1 and 2 of the accompanying drawings.