GB2260662A

GB2260662A - Vehicle deceleration indicator

Info

Publication number: GB2260662A
Application number: GB9122199A
Authority: GB
Inventors: Philip Graham Horton
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-10-18
Filing date: 1991-10-18
Publication date: 1993-04-21
Also published as: GB9122199D0

Abstract

The indicator comprises a pendulum 21 operating a switching system 7, 8, 9, 10, 22 to cause a plurality of lights to be energised in sequence as the degree of deceleration increases. The pendulum may carry a magnet 22 to operate reed switches 7, 8, 9, 10. Alternatively, the pendulum may operate direct mechanical contacts, or adjust a resistor connected to an electronic circuit controlling the lights, or light sensitive switches may be used. The indicator system is enabled by a relay (18), (Fig 3), energised by the normal brake switch (6) or by a test switch (25). The reed switches 7 to 10 energise respective self-latching relays (11) to (14) so that pairs of lights (2) to (5) are energised in sequence with increasing deceleration, whereby the number of lights energised indicates the degree of deceleration. Opening of the brake switch (6) allows the relays (11) to (14) to unlatch. <IMAGE>

Description

MOTOR VEHICLE DECELERATION INDICATOR THIS INVENTION RELATES TO A MOTOR VEHICLE DECELERATION INDICATOR.

INTRODUCTION For the past sixty years, motor vehicles have bern equipped with simple stop lights that warn following vehicles that brakes are being applied. In modern vehicles, this 15 configured by the incorporation of a switch which senses pressure in the vehicles hydraulic braking system and displays two red lights on the rear of the vehicle.

No significant improvement in the quality of warning has been introduced despite the fact that standard production vehicles are now capable of high speeds and have highly efficient braking systems. Standard equipment can now include radial tyres, dual circuit brakes, servo-assistance, GBS etc. With the abundance of motorways, allowing sustained, high speed motoring, a single indication of braking is inadequate.

This invention provides a true display of the rate of deceleration of a vehicle allowing following motorists comprehensive information, thereby reducing the risk of under-reaction/collision or over-reaction/loss of control.

According to the present invention, there is provided a motor vehicle deceleration indicator comprising a pendulum switch, co-operating with circuitry to illuminate an array of lights in sequence dependant upon the forces exerted on the pendulum by the deceleration of the vehicle.

specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings and wiring diagram in which: FIGURE 1 SHOWS: A) n Pendulum 21 mounted and free to move in d single axis 24.

B) A Bar Magnet 22 mounted to the pendulum.

C) Four Dry Magnetic reed switches 7,8,9 a 10 set at specified angles within the magnetic span.

D) Rngle 24 of movement of pendulum when subjected to a maximum deceleration.

E) Angle 23 of movement of bar magnet when subjected to maximum deceleration.

FIGURE 2 SHOWS-- Typical rear of motor vehicle showing two options for mounting.

Option 19 Additional brake lights reference 1,2,3,4 & 5 arranged in pairs along the bottom of the rear window.

Option 20 (incorporated in new vehicles).

Additional brake lights reference 2,3,4 & 5 arranged in pairs between existing brake lights.

FIGURE 3 SHOWS: The Associated wiring diagram.

1. Vehicles standard brake lights.

2. Additional brake lights in pairs.

3. Additional brake lights in pairs.

4. Additional brake lights in pairs.

5. Additional brake lights in pairs.

Vehicles existing hydraulic brake switch.

7. 1st Dry reed magnetic switch.

8. 2nd Dry reed magnetic switch.

9. 3rd Dry reed magnetic switch.

10. 4th Dry reed magnetic switch.

11. 1st Relay 4 pole Normally open/Normally open.

12. 2nd Relay 4 pole Normally open/Normally open.

13. 3rd Relay 4 pole Normally open/Normally open.

14. 4th Relay 4 pole Normally open/Normally open.

15. Auxillary fused Electrical Supply.

16. Vehicles Existing brake light Electrical Supply.

17. Vehicles Existing negative (ground).

18. Energising relay 2 pole Normally open.

25. Test Switch.

FIGURE 4 SHOWS:- General Arrangement of pendulum switch assembly.

7-10 Reed Switches.

11-14 Relays.

18 Energising Relay.

22 Bar Magnet.

25 Test Switch.

26 Adjustable Mounting Bracket.

27 Switch Cover.

28 Inspection Cover.

29 Test Lever.

SEQUENCE OF OPERATION Referring to Fig.1. the indicator comprises a pendulum 21 onto which is mounted a bar magnet 22. Under the forces of decelaration, the pendulum 21 moves forward and, in doing so, causes the bar magnet 22 to scan the dry reed switches 7,8,9 & 10 and close in sequence.

Referring to Fig.3. the operation of the vehicles brakes causes hydraulic pressure switch 6 to close (this is part of the vehicles standard brake indication). Nn electrical feed is taken from the switched contact 6 which closes relay 18 thereby energising the deceleration indicator. fls the pendulum 21 moves forward under the progressive forces of deceleration four independant electrical circuits are completed in sequence. These close relays 11,12,13 & 14 respectively which illuminate additional rear lights 2,3,4 & 5 arranged in pairs starting at the outside of the vehicle and progressing towards the centre. Thus the rate of deceleration is directly indicated by the number of lights illuminated.

By the incorporation of auxillary relay contacts, wired as shown, the relays, once energised by their respective reed switches 7,8,9 & 10, latch in and remain closed. This ensures that the maximum deceleration in any one instance is displayed, even when the vehicle has come to rest as an additional warning.

On release of the brake pedal, switch 6 opens releasing relay 18 which allows relays 11,12,13 & 14 to unlatch simultaneously.

ALTERNATIVES The indicator as described magnetically operates dry reed switches. There are a number of alternative devices that perform a similar function such as: Direct mechanical contacts.

8) Resistance Modulation co-operating through solid state electronics.

C) Light sensitive switches.

There are also indirect methods of monitoring deceleration such as: A) Multiple Sensing of increased hydraulic brake pressure.

B) Reduction in revolutions of drive shafts.

However these cannot be accurately calibrated and may give spurious readings.

relevant factor in the invention is that it measures ACTUAL deceleration and by ensuring that all devices are calibrated to switch at pre-determined deceleration rates gives a consistant readout from all vehicles which can be learnt arid recognised.

INSTALLATION The pendulum switch is equipped with an adjustable mounting bracket 26 which ensures that, on mounting the device at a convenient position, adjustment can be made to ensure that the device is vertical.

Electrical connections are made in accordance with wiring diagram Fig.3.

Note that road gradients have a minimal effect on the switching positions therefore self levelling characteristics are unnecessary.

MAINTENANCE To permit visual checks on the mechanical and electrical functioniny of the indicator, a test switch 25 is incorporated. By closing this switch, the indicator can display its function whilst the vehicle is stationer-y. By manually swinging pendulum 21 with the test lever 29, all circuitry and bulbs may be checked for function. By opening the test switch 25, the circuitry reverts to normal operation.

Additionally, where vehicle is suitably equipped, bulb checking could be added to existing circuitry.

Claims

CLNIMS

1. R motor vehicle deceleration indicator comprising a pendulum switch, co-operating with circuitry to illuminate an array of lights in sequence dependent upon the forces exerted on the pendulum by deceleration of the vehicle.

2. R motor vehicle deceleration indicator as claimed in 1 wherein the pendulum, moving under the forces exerted by deceleration, co-operates to cause an activator to initiate switching signals in sequence.

3. A motor vehicle deceleration indicator as claimed in 1 and 2 wherein the switching signals co-operate to cause relays to operate allowing lights to illuminate in sequenced pairs.

4. A motor vehicle deceleration unit as claimed in 3 wherein relays are configured, through auxillary contacts, to latch in and stay energised without a sustained switching signal.

5. g motor vehicle deceleration indicator as claimed in 4 wherein the relays are unlatched by the interruption of power from the braking system of the vehicle allowing circuitry to be re-set.

6. n motor vehicle deceleration indicator as claimed in 1 wherein the device can be checked for operation by the use of test switch and test lever.