GB2038115A

GB2038115A - Motor vehicle deceleration alarm device

Info

Publication number: GB2038115A
Application number: GB7849492A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-12-20
Filing date: 1978-12-20
Publication date: 1980-07-16
Also published as: GB2038115B

Abstract

An audible and/or visual alarm to warn other vehicles of violent deceleration of a motor car, irrespective of the application of the brakes of the car, is provided by an inertia arm or pendulum which actuates a microswitch (11) in the event of deceleration exceeding a predetermined magnitude. The microswitch (11) controls the flow of current from a power terminal (19) to the coil (22) of a relay (13). An armature of the relay (13) closes two pairs of contacts (20, 25; 21, 26) so that current may flow through a normally closed switch (14) to maintain the relay coil energised. Current flows through the second pair (21, 26) of contacts to light warning bulbs (27, 28) at the rear of the vehicle. The device is reset by opening the switch (14) and is adjustable to respond to different deceleration levels. <IMAGE>

Description

SPECBEICATION Alarm device The present invention concerns an alarm device particularly for use in a motor vehicle to indicate when a predetermined level of deceleration of the vehicle has been reached or exceeded.

Motor vehicles are provided with brake warning lights at the rear of the vehicle which are actuated in response to depression of a brake pedal and give warning of braking to other vehicles to the rear. Whilst this is a very useful warning system giving, as it does, an immediate visual warning prior to perceived shortcoming of the space between the vehicle and vehicles following, it has a number of shortcomings. One such shortcoming lies in the fact that the brake lights are actuated irrespective of the degree of braking. Another shortcoming is that the brake lights are deactuated as soon as foot pressure is removed from the brake pedal, for example following a collision accident involving the braking vehicle.In this latter case the vehicle involved in the collision still presents a hazard to following vehicles, especially in conditions of low viability but the brake lights do not provide a continuing warning of the hazard. Still a further shortcoming of conventional brake lights lies in the fact that they are actuated only in response to depression of the brake pedal so that a sudden deceleration caused by collision without braking does not activate the brake lights.

Bt is an aim of the present invention to overcome some or all the shortcomings of the conventional vehicle brake light system.

With this aim in mind the present invention provides a motor vehicle deceleration alarm device comprising switch means for actuating an audible and/or visual alarm, and means sensitive to deceleration and operative, in the event of deceleration of the vehicle reaching or exceeding a predetermined value, to actuate said switch means.

Preferably, means is provided for maintaining the alarm in an actuated state once decel eration has reached or exceeded the predeter mined value. In this case manual means are advantageously provided for re-setting the alarm to return it to its initial state.

The present invention will hereinafter be further described by way of example with reference to the accompanying drawings in which: Figure 1, is a plan view of an alarm device constructed in accordance with the invention and including a housing, a cover for the housing being removed; and Figure 2 is a circuit diagram of the alarm device of Fig. 1.

Preferring firstly to Fig. 1 the exemplified alarm device comprises a plastics box-like housing 10 in which is disposed a microswitch 11, an inertia arm 1 2 for actuating the microswitch, a two-pole normally-open relay 13 and a reset button-switch 14. Input and output connections to the device are made by means of a termainal block 1 5 attached to the outside of the housing, connections between the terminal block and the internal components being made by plastics-coated wires 1 6.

The inertia arm 1 2 consists of a metal strip attached to a lever arm 1 7 pivotable about ist point of attachment to switch 11 to depress a spring-loaded button 1 8 thereby closing switch 11. Expanded foam cushioning is provided at both extremes of the movement of one end of arm 1 2. The housing 10 is provided with means, not shown, for attachment to a convenient portion of the vehicle body said means preferably allowing adjustment of the orientation of the housing relative to the vehicle.It will be understood that when the device is mounted on a vehicle such that the device normally moved with the vehicle to the left as seen in Fig. 1, then any deceleration of the vehicle will cause arm 1 2 to tend to pivot in an anticlockwise sense so that lever 1 7 acts on switch button 1 8. For a given deceleration it will be understood that the force acting on button 1 8 will depend on the orientation of arm 1 2 (and therefore the device as a whole) relative to the vehicle. Thus by adjusting the orientation of the housing 10 the deceleration at which button 1 8 is depressed to actuate switch 11 may be varied.

Clearly other means may be employed for actuating switch 11 in response to decleration. For example, arm 1 2 could be replaced by a pendulum suspended from an upper portion of the housing 10 (the alarm in this case being mounted in a vertical plane) with the free end of the pendulum arranged to swing against button 1 8 in the event of severe deceleration.

Referring to Fig. 2 it will be seen that a voltage input 1 9 is connected to terminals 20 and 21 of relay 13 and also, by way of switch 11, to one side of a coil 22 and to a terminal 23 of a push-button switch 1 4. Switch 1 4 is normally closed so that terminal 23 is connected to a terminal 24 and thereby to a terminal 25 of the relay 1 3. A further contact terminal 26 is connected to warning lamps 27 and 28 connected in parallel and disposed at the rear of the vehicle. Alternatively or additionally, a horn could be connected between termanal 26 and earth for the provision of audible warning.

Assuming rapid decelleration pivots arm 1 2 (Fig. 1) to depress button 18 and close switch 11 then current flows from terminal 1 9 through coil 22 of the relay 1 3 to earth. With coil 22 activated contacts 20 and 25 and 21 are bridged and warning lamps 27 and 28 are switched on. At the same time current flows between contacts 20 and 25, through switch 14 to coil 22 so that coil 22 remains acti vated even when switch 11 opens when the magnitude of deceleration falls below the predetermined value. Thus, lamp 27 and 28 remain lit until reset button switch 1 4 is opened by pressing whereupon current to coil 22 is discontinued, the relay contacts are opened and current to the lamps and to coil 22 ceases to flow until switch 11 is once more closed. Only in the event of severe deceleration is switch 11 closed to light the warning lamps but this takes place irrespective of whether or how hard the brakes are applied. Therefore, in the event of a sudden collision without application of brakes, the warning lights are switched on and remain on as a continuous warning to following traffic, this being a particular advantage in foggy conditions,

Claims

1. A motor vehicle deceleration alarm device comprising switch means for operating an audible and/or visual alarm, and means sensitive to deceleration and operative, in the event of deceleration of the vehicle exceeding a predetermined value, to actuate said switch means.

2. A device as claimed in claim 1 further comprising means operative to maintain said alarm in an activated state after deceleration has been completed.

3. A device as claimed in claim 1 or 2 in which the switch means comprises an electromagnetic relay.

4. A motor vehicle deceleration alarm device substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

4. A device as claimed in claim 3 in which the means sensitive to deceleration comprise an inertia element disposed so as to actuate a switch controlling current supply to a relay whereby the relay is activated in the event of deceleration exceeding said predetermined value.

5. A device as claimed in claim 4 in which the relay armature controls two relay switches so that when the relay is activated both relay switches are closed and current may pass through one of the relay switches, through a normally closed reset switch connected in series therewith, to a coil of the relay such that the relay remains activated after completion of deceleration and current continues to pass through the other relay switch to actuate the alarm until the reset switch is opened.

6. A motor vehicle deceleration alarm device substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

CLAIMS (14 April 1980)

1. A motor vehicle deceleration alarm device comprising switch means for operating an audible and/or visual alarm, and means sensitive to deceleration and operative, in the event of the rate of deceleration of the vehicle exceeding a predetermined value, to actuate the switch means, said switch means comprising an electromagnetic relay operative to maintain said alarm in an activated state after actuation of the switch means.

2. A device as claimed in claim 1 in which the means sensitive to deceleration comprises an inertia element disposed so as to actuate a microswitch controlling current supply to the alarm and the electromagnetic relay.

3. A device as claimed in claim 1 or 2 in which an armature of the electromagnetic relay controls two relay switches so that when the electromagnetic relay is activated both relay switches are closed and current may pass through one of the relay switches, through a normally closed reset switch connected in series therewith, to a coil of the electromagnetic relay remains activated after actuation of the switch means.