GB2113933A - Improvements in fuel economy indicators - Google Patents

Abstract

A fluid flow indicator has a transducer (10) connectible for example to an inlet manifold of an internal combustion engine, whereby changes in the vacuum in the manifold create movement of a biassed control member (16). The latter moves a mask (22) with a profiled opening (24) between LEDs (26) and photo- transistors (28), which control operation of transistors (forming part of circuit 30) and consequently pairs of LEDs (not shown) (32) at an output display. <IMAGE>

Description

SPECIFICATION Improvements in fuel economy indicators This invention is concerned with improvements in or relating to fluid flow indicators, and is particularly useful for providing indications of rate of fuel consumption in an engine, or providing indications of level of combustion in a fuel burning device.

Various types of apparatus have been proposed for use with autamobile engines to provide an indication of the rate of consumption of fuel, the apparatus communicating with the inlet manifold of the engine whereby the varying vacuum in the manifold control mechanical gauges. It has also been proposed to provide a transducer which converts the mechanical movement into an electrical signal, usually an analogue signal, which is then transmitted to an electrical indicator mounted on the dash-board of the vehicle.

According to the present invention there is provided apparatus for indicating the flow of a fluid medium in a device, said apparatus comprising means operatively connectible with the fluid flow path in the device and adapted to translate changes in flow rate of the fluid into movement of a control member, the latter being located relative to an arrangement of energy transmitting and receiving means, whereby the movement of the control member affects the passage of the energy, the energy transmitting and receiving arrangement being connected in an electrical circuit for presenting an encoded output display.

Preferably, the control member comprises a mask defining a profiled opening and being movable in a location between transmitters and receivers of said arrangement, whereby the position of the opening controls which receivers receive energy from the transmitters and thus controls a digital output display.

The transmitters may comprise infra-red light emitting diodes (LEDs) and the receivers may comprise photo-transistors. The circuit may include a plurality of further LEDs controllable in a coded manner.

Preferably also, the means for translating changes in the flow rate into movement of the control member comprises a transducer having a spring-biased diaphragm. The transducer is preferably connectible to an inlet manifold of an internal combustion engine to effect movement of the diaphragm, and consequently movement of the control member which is connected thereto, in accordance with changes in vacuum in the manifold.

An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings, wherein: Fig. 1 is a diagrammatic view of an apparatus according to the inventions; and Fig. 2 is a schematic circuit diagram.

Referring to the drawings, an apparatus for use in an automobile to provide an indication of continuing fuel consumption as a consequence of the varying pressures in an inlet manifold of the vehicle engine, comprises a transducer 10 defining a housing having an integral cavity 12 across which extends a diaphragm 1 4. The latter mounts a control member 1 6 extending through one end of the transducer housing to one side of the diaphragm 14, a compression spring 1 8 being Jocated in the cavity 1 2 to extend between said other end of the transducer housing and the opposed side of the diaphragm 14. The spring 18 so biases the diaphragm 1 4 that the control member 1 6 is biased outwardly of the tranducer housing.At said other end the transducer housing has an opening 20 adapted to communicate by any suitable means with the inlet manifold (not shown) of the vehicle engine.

The control member 1 6 includes a mask 22 defining a profiled opening 24 therein. To one side of the mask 22 there are positioned a bank of three energy transmitters 26 for example infra-red LEDs, and to the other side of the mask 22 there are positioned a bank of energy receivers 28, for example in the form of photo-transistors. Each of the transmitters 26 is aligned with a respective one of the receivers 28, whereby energy is transmitted in a straight path therebetween.

Movement of the control member 16 and therefore the mask 22, in accordance with changes in pressure in the inlet manifold, alters the position of the profiled opening 24 with respect to the transmitters 26 and the receivers 28, whereby to enable energy to be received, in the one extreme position, by all the receivers 28, and to be received, in the other extreme position, of movement by none of the receivers 28. The transmitters 26 and the receivers 28 are connected in an electrical drive circuit 30. With reference to Fig. 2, the circuit 30 includes a bank of further LEDs 32, the latter being arranged to be switched on and off in pairs.Specifically there are seven LEDs 32a to 32g, the LEDs 32a and 32g being in one branch circuit, the LEDs 32b and 32f being in another branch circuit, the LEDs 32c and 32e being in a further branch circuit, and the LED 32d being connected permanently across the voltage input terminals which can be electrically connected to any suitable point on the circuitry of the vehicle. In operation, there is a continual display by the LED 32d and, as the rate of fuel consumption increases, the mask 22 firstly allows energy to be transmitted to the receiver 28a, which controls operation of a transmitter 34a, the latter energising the LEDs 32c and 32e. A further increase in fuel consumption switches the receiver 28b in addition to the receiver 28a, and the former controls operation of a transistor 34b, whereby to switch on the LEDs 32b and 32f.Finally, further consumption switches receiver 28c to control -operation of a transducer 34c and thus switch on the LEDs 32a and 329. In this way, a digitally encoded output display is achieved and the LEDs 32 can be housed in any suitable device for mounting on the dashboard of the vehicle. The display is thus illuminated progressively as the inlet manifold vacuum is decreased, providing a very acceptable presentation to the driver of the vehicle.

The mask 22 may be removably mounted on the control member, whereby masks having different profiled openings may be utilised to adapt apparatus if necessary to the parameters of different vehicles. An apparatus has therefore been provided which is simple to manufacture and service, and which can present a simple but very acceptable digitally encoded display.

In another use of the invention, the transducer housing communicates, by means of opening 20 and other suitable means with the flow path of the combustion gases in a fuel burning appliance such as a solid fuel fire or gas fire. The apparatus operates in the manner previously described in accordance with changes in pressure due to changes in the flow rate of the combustion gases, which is indicative of the level of combustion in the appliance.

Thus an indication of the continuing level of combustion can be provided in a very acceptable presentation at a suitable remote location to enable control of the appliance.

It will be appreciated that further circuitry and instrumentation may be provided whereby different forms of digital display, for example a numerical display, may be provided if required.

Various modifications may be made without departing from the invention. For example forms of energy different to infra-red may be utilised and the number of transmitters and receivers and display indicators may be varied as necessary.

Further the means for converting changes in pressure to movement of the mask may also vary from that described and shown.

Claims (11)

1. Apparatus for indicating the flow of a fluid medium in a device, said apparatus comprising means operatively connectible with the fluid flow path in the device and adapted to translate changes in flow rate of the fluid into movement of a control member, the latter being located relative to an arrangement of energy transmitting and receiving means, whereby the movement of the control member affects the passage of the energy, the energy transmitting and receiving arrangement being connected in an electrical circuit for presenting an encoded output display.

2. Apparatus according to claim 1 wherein the control member comprises a mask defining a profiled opening and being movable in a location between transmitters and receivers of said arrangement, whereby the position of the opening controls which receivers receive energy from the transmitters and thus controls a digital output display.

3. Apparatus according to claim 2, wherein there are provided three transmitters and correspondingly three receivers.

4. Apparatus according to claim 2 or 3, wherein the transmitters comprise infra-red light emitting diodes.

5. Apparatus according to any of claims 2 to 4, wherein the receivers comprise photo-transistors.

6. Apparatus according to any of the preceding claims, wherein the output display comprises a plurality of light emitting diodes controllable in a coded manner.

7. Apparatus according to claim 6, wherein the light emitting diodes of the output display are controllable in pairs by transistors.

8. Apparatus according to claim 7, wherein the output display comprises three of said pairs of diodes, respective ones of each pair being located on opposite sides of a central light emitting diode which is connected permanently in the circuit.

9. Apparatus according to any of the preceding claims, wherein the means for translating changes in the flow rate into movement of the control member comprises a transducer having a springbiased diaphragm.

10. Apparatus according to claim 9, wherein .the transducer is connectible to an inlet manifold of an internal combustion engine to effect movement of the diaphragm, and consequently movement of the control member which is connected thereto, in accordance with changes in vacuum in the manifold.

11. Apparatus for indicating the flow of a fluid medium in a device substantially as herninbefore described with reference to the accompanying drawings.