GB2533990A

GB2533990A - Horn Switch

Info

Publication number: GB2533990A
Application number: GB1516075.7A
Authority: GB
Inventors: Jacob Budge Thomas
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-01-12
Filing date: 2015-09-10
Publication date: 2016-07-13
Also published as: GB201516075D0; GB201500441D0

Abstract

A motor vehicle has a steering wheel 2 which may have a boss and is connected to a steering shaft 5. Located within said boss may be a spring loaded button switch 3, a microswitch 12, a radio transmitter10 and associated battery 11. Depressing the switch 3, activates the microswitch 12 causing the radio transmitter 10 to send a predetermined signal to a remote radio receiver 13. The receiver is powered by a vehicle battery 1 and is connected to a relay 14. When the signal is received the relay closes and the vehicle horn 6 is sounded. The transmitter, battery and microswitch may be a single unit that is generally toroidal in shape to locate within said boss. The transmitter may send an RF or Bluetooth (RTM) signal to the receiver. The device is intended to be retrofitted to vehicles where modifications have been made to the steering column.

Description

Intellectual Property Office Application No. GII1516075.7 RTM Date February 2016 The following terms are registered trade marks and should be read as such wherever they occur in this document: Bluetooth Intellectual Property Office is an operating name of the Patent Office www.gov.uk/ipo

HORN SWITCH

The present invention relates to horn switches. More particularly it relates to horn switches for use in motor vehicles.

By law motor vehicles must be fitted with a horn. For at least the last seventy years the horn has been an electric horn operated by a switch and powered by the vehicle's electrical system. Conventionally the horn switch is mounted on the steering wheel so it can be reached quickly in an emergency. Often it is operated by pressing a large button or pad in the centre of the wheel.

Because the steering wheel rotates it is necessary to connect the horn switch to the horn in a way that allows the switch to operate while being rotated two or three times in both directions. In vehicles with worm drive steering it is common to have a hollow steering shaft. The end of the shaft carrying the worm gear is mounted in a steering box and is supported in a bearing supported in the steering box wall. A wire passes down the shaft and exits through an aperture in the steering box wall which in concentric to the bearing and thus in line with the axis of the steering shaft. The length of the wire and its free movement within the shaft allows the horn switch to rotated two or three times in either direction without straining the wire.

In more modern vehicles rack and pinion steering has replaced worm drive because it offers a more direct response and is more suited to use with power steering. The different layout and requirements of rack and pinion steering mean that it is not possible to run wires down a hollow steering shaft and out of the steering box, as was possible in the older worm drive design. To overcome this, manufacturers have used various solutions such as slip rings and pancake slip rings to allow the horn switch to be connected to the horn while still permitting free rotation of the wheel. The slip ring allows the wheel to be rotated as many turns as required in either direction while still maintaining contact between switch and horn. Such slip ring arrangements tend to be built into the steering wheel mount and the steering wheel mount surround.

It is sometimes desirable to replace the worm gear steering on an older vehicle with a rack and pinion system. For example, there is wide interest in keeping vintage VW microbuses running but modern users want the vehicles to be more roadworthy, reliable and driveable than they were as originally built. However at the same time, users want the vehicle to look as authentic as possible and certainly to use the original steering wheel.

Rack and pinion conversion kits for such vehicles are well-known. However there arises a problem with such conversions in that the wiring for the horn switch can no longer be routed through the steering both.

This is a substantial problem for users who wish to stay with the existing steering wheel and horn switch position. Some users replace the horn switch with a dashboard-mounted button. Others have tried fitting slip rings to the VW steering wheel. This, however, is time-consuming, bulky and unreliable since the steering mount was not designed to take slip rings in the first place. There is no effective way of getting an electrical connection to the centre of the rotating steering wheel in such replacement kits.

According to the present invention there is provided a horn switch system for operating the horn of a motor vehicle steered by a steering wheel and incorporating a horn button in the steering wheel, characterised in that the horn switch comprises a radio transmitter mountable in the steering wheel and powered by its own power supply also mountable in the steering wheel, switching means operable by the said horn button to cause the said radio transmitter to transmit a predetermined signal and a receiver mountable away from the steering wheel which receiver switches power to the said horn on receiving the said predetermined signal.

Preferably the said radio transmitter and own power supply are incorporated in a single unit that is mountable in the boss of the said steering wheel.

Preferably the said radio transmitter uses an RF signal to transmit the said predetermined signal. Preferably the said switching means are incorporated in the said single unit. Preferably the said single unit is substantially toroidal in plan.

Preferably the said transmitter and receiver include means for changing the said predetermined signal.

The invention will be further described with reference to the accompanying drawings in which: Figure 1 shows a schematic of known horn system for use in a motor vehicle Figure 2 shows a schematic of another known horn system for use in a motor vehicle Figure 3 shows a horn system embodying the current invention Figure 1 shows a schematic diagram of a known horn system in a motor vehicle. The vehicle includes a battery 1 which is used to power all the vehicle electrics and a steering wheel 2 which is used to control the direction of the vehicle. Mounted in the boss of the steering wheel is a spring-loaded button 3. Behind the button and within the steering wheel is a normally-open microswitch 4. The steering wheel is mounted on a hollow shafts.

An electrically operated horn 6 is mounted in the vehicle, away from the steering wheel in a location where it can easily be heard outside. The horn is connected to the live side of the battery. A wire 7 runs from the horn 6, through the centre of the hollow shaft 5 and is connected to one side of the microswitch 4. The other side of the microswitch 4 is connected to the vehicle chassis, as is the earth side of the battery 1. When the button 3 is pressed, the microswitch 4 is closed, a circuit is made and the horn sounds.

Figure 2 shows a schematic diagram of a variant of the horn system of Figure 1. In this variant, the steering wheel shaft is a solid shaft 8. The switch is still mounted in the steering wheel boss but connection is made to the battery via a slip ring 9. In all other ways the system of Figure 2 is identical to that of Figure 1.

Figure 3 shows a schematic diagram of a horn system incorporating the current invention. As before, the vehicle includes a battery 1 which is used to power all the vehicle electrics and a steering wheel 2 which is used to control the direction of the vehicle. Mounted in the boss of the steering wheel is a spring-loaded button 3. The steering wheel is mounted on a shaft 5.

Within the boss of the steering wheel, behind the button 3, is mounted a small radio transmitter 10 powered by a dedicated built-in battery 11. The transmitter 10 is connected to a microswitch 12.

When the button 3 is pressed the microswitch 12 is switched and the transmitter 10 transmits a predetermined signal.

Away from the steering are mounted an electrically operated horn 6 and a radio receiver 13. The radio receiver is powered by the vehicle battery 1 and is connected to a normally-open relay 14, which relay it closes when it receives a predetermined signal from the transmitter 10. One terminal of the horn is connected to the live side of the battery and the other to one side of the normally-open relay 14. The other side of the relay 14 is connected to the vehicle chassis, as is the earth of the vehicle battery 1. When the horn button 3 is pressed, the radio receiver 13 receives the predetermined signal, closes the relay 14 and causes the horn to sound.

In the embodiment described, the transmitter and battery are housed in a single unit together. The unit is substantially toroidal in shape. This means that it effectively self-locates in the space in the boss of the steering wheel, with the microswitch in the right position to be operated by the horn button.

In the embodiment shown the predetermined signal is an RE signal It will be envisaged that the signal could be a Bluetooth signal, or any other known radio signal.

Claims

CLAIMS1. A horn switch system for operating the horn of a motor vehicle steered by a steering wheel and incorporating a horn button in the steering wheel, characterised in that the horn switch comprises a radio transmitter mountable in the steering wheel and powered by its own power supply also mountable in the steering wheel, switching means operable by the said horn button to cause the said radio transmitter to transmit a predetermined signal and a receiver mountable away from the steering wheel which receiver switches power to the said horn on receiving the said predetermined signal.
2. A horn switch system as claimed in claim 1, wherein the said radio transmitter and own power supply are incorporated in a single unit that is mountable in the boss of the said steering wheel.
3. A horn switch system as claimed in either of claims 1 or 2, wherein the said radio transmitter uses a RE signal to transmit the said predetermined signal.
4. A horn switch system as claimed in either of claims 1,2 or 3, wherein the said switching means are incorporated in the said single unit.
5. A horn switch system as claimed in any preceding claim, wherein the said single unit is substantially toroidal in plan.
6. A horn switch system as claimed in any preceding claim, wherein the said transmitter and receiver include means for changing the said predetermined signal.
7. A horn switch system substantially as hereinbefore described with reference to the accompanying drawings.