GB2239823A

GB2239823A - Electrically conductive nozzle assembly

Info

Publication number: GB2239823A
Application number: GB9000934A
Authority: GB
Inventors: Melvyn Russell Mitchell; Roger Broughton
Original assignee: Pressac Ltd
Current assignee: Pressac Ltd
Priority date: 1990-01-16
Filing date: 1990-01-16
Publication date: 1991-07-17
Also published as: DE4100884A1; GB9000934D0

Abstract

A nozzle assembly for providing jets of fluid for washing vehicle windscreens or headlamps. A body 11 of the assembly is composed of an electrically conductive material, for example, a plastic, so that the assembly may be heated when a current is passed through it in order to prevent the formation of ice on cold conditions. A connector portion 10 provides means for delivering fluid to a nozzle portion 18 of the body 11 and supports electrical connecting means for connecting an electrical supply to contacts 34, 38 engaging the body. The assembly may also contain a means 25 for regulating the electrical current. <IMAGE>

Description

1 NOZZLE ASSEMBLY This invention relates to a heated nozzle assembly for

producing jets of fluid particularly for washing windscreens or headlamps of vehicles.

The fluid used in washing windscreens and the like is typically a mixture of water and detergent. A problem which is commonly experienced is that washer nozzles may freeze during cold weather, rendering them inoperative. Consequently, heated nozzle assemblies have been proposed. These existing designs are heated by means of an electric cartridge heater housed within the nozzle assembly. Such heaters sometimes fail, however, so that such nozzle assemblies are not completely reliable. Additionally, because of the bulk of the heater, the source of heat is localised at a position remote from the nozzle opening which is the part most likely to become frozen. Furthermore, in initial manufacture the time and cost of inserting the cartridge heater as well as the cost of the heater itself are significant.

One object of the present invention is to provide an improved heated nozzle assembly.

The present invention is directed, in one aspect, towards a nozzle assembly suitable for use in projecting a fluid spray, comprising a nozzle portion including a body of electrically conductive material having a channel through which fluid may be supplied to a nozzle opening in use, a connector portion adapted 1 2 to mate with the body, and electrical contacts mounted in the assembly to engage the body at spaced locations, whereby an electrical current may be passed through the body.

An assembly in accordance with the invention does not rely on a cartridge heater. A preferred embodiment of the invention makes use of electrically conductive plastics material to make the body of the assembly. The material's resistance allows the body of the assembly itself to produce the required heat.

In the preferred embodiment, the body comprises a sleeve portion adapted to slidingly receive the connector portion in mating engagement with the body.

Suitably the connector portion of the assembly may support the electrical connecting means by which an electrical supply may be connected to the contacts. The electrical connecting means preferably includes temperature controlling means, e.g. a thermistor, adjacent to the body whereby to sense the temperature of the body, and adapted to regulate the current flow through the body to maintain the body at a desired temperature.

In the embodiment described herein by way of example the temperature controlling means is arranged to bear on a separate contact which itself makes electrical contact with the conductive body; in an assembly in accordance with the invention 3 the thermistor (or other temperature controlling means) may, however, be arranged to bear directly on the body to make a direct contact.

Indeed, in another assembly in accordance with the invention, the electrically conductive body may have a low resistance and most of the heat may be generated by the thermistor also acting as a temperature controlling means, a positive temperature coefficient device of commonly known characteristics. This construction is, however, still simpler, cheaper and more effective than the known use of cartridge heaters.

In yet a further nozzle assembly in accordance with the invention the electrically conductive body itself may be moulded in a material having a positive temperature coefficient. In that case the body itself not only generates the necessary heat but also is self-regulating in a manner well known to those familiar with positive temperature coefficient devices.

Preferably, the connector portion of an assembly in accordance with the invention comprises locating means adapted to position at least one of said contacts for engagement with the body. said body comprising a passage in which said contact is adapted to be slidingly received when the connector portion is moved into mating engagement with the body.

4 There now follows a detailed description, to be used with reference to the accompanying drawings of a nozzle assembly embodying the invention. It- will be realised that this nozzle assembly has been selected for description to illustrate the invention by way of example.

In the accompanying drawings:- Figure 1 is a view in section through a complete assembly; Figure 2 is a view in side elevation of a non-conductive connector of the illustrative nozzle assembly; Figure 3 is a view in section though the connector along III-III of Figure 2; Figure 4 is an underneath plan view of the connector; i 1 Figure 5 is a view in section through a condudtive body of the illustrative nozzle assembly; Figure 6 is a view in front elevation, partly in section, of the conductive body; and Figure 7 is an underneath plan view of the conductive body 1 i 1 Figure 1 shows the illustrative nozzle assembly, in which a connector portion 10 and a body 11 are close-fitting; the assembly may be sealed, for example, by cementing or ultrasonic welding along the join between the body 11 and a shoulder 13 of the connector portion or by enclosing the sleeve of the body and the connector portion within a heat-shrunk sleeve to prevent water entry between the connector portion 10 and the body 11.

The connector portion 10 is of a cross sectional shape corresponding to the cross-sectional shape of an opening in a sleeve portion of the body 11 in which the portion 10 is received, and can only be located correctly therein in one predetermined orientation. The connector portion 10 may be made, for example, from nylon A125. The connector portion 10 comprises a pipe 12 through which fluid, typically water mixed with antifreeze and/or a detergent, can enter (Figures 1 and 2) from a hose attached to the end thereof (not shown), a conduit 17 and a terminal portion 14 through which the conduit 17 extends. The terminal portion 14 is tapered, allowing said terminal portion 14 to make close contact with a corresponding socket portion 16 (Figure 5) of the body 11, in order to form a continuous fluid passage running through the assembly to a channel 15 and then to a nozzle opening 18 of the body 11. The contact between terminal portion 14- and socket portion 16 should be close. It is essential that no leakage of fluid between the portions 14, 16 occurs, otherwise the risk that a damaging short circuit will arise is substantial. Accordingly to effectively 1 6 seal the fluid channel, preventing said fluid from coming into contact with any other parts of the assembly, the terminal portion, portion 14, and socket portion 16 are sealed together, for example using a suitable cement or ultrasonic welding, to prevent fluid leakage. Body 11 is electr. ically conductive, and preferably is injection moulded from any suitable conductive plastics material, for example, Stat-kon, made by LNP.

The electrical contacts and connecting means of the illustrative assembly are arranged as follows. one contact 34 is placed in a slot 20 of the connector portion 10 (Figure 3), where it is held such that the suitably adapted contact enters slot 22 (Figure 6) of body 11 when the body and connector are placed in mating engagement (see Figure 7). A second contact 36 (Figure 1) is housed in pocket 24 (Figure 3), where electrical contact is made with a thermistor 25 in a recess 26 in the connector portion 10. Contact between body 11 and thermistor 25 may be made via a metal strip contact 38 placed in slot 30 of the body (Figure 1).

In order to produce a completed assembly, contacts are first positioned in the connector portion in slot 20 and pocket 24, and the connector is slid into the body, causing contact 34 to enter slot 22 of the body 11. Contact 38 has a dimple 40 which moves along recess 42 until the body and connector portion are in the final position, at which time dimple 40 abuts against thermistor 25. A good electrical contact is ensured by the 11 i 7 combination of forces resulting from the dimple 40 pressing on one side of the thermistor 20 and contact 36 pressing on the other side, contact 36 being put under tension by projection 28 and having a sprung end portion 39 urged against the thermistor 25.

When in use, the assembly may be placed in an aperture in a vehicle body, f or example, partially restrained by the enlarged head 32 of the body 11 with the nozzle opening 18 directed at a part of the vehicle to be washed e.g. a windscreen, or headlamps. Fluid is then forced in a jet from the nozzle opening 18, in known manner.

other embodiments are possible. For example, the nozzle opening 18 may be adapted to hold swivel nozzle. In another form, there may be more than one nozzle opening, each set at an angle to the next so that each jet is directed to a different area of the windscreen, for example.

In cold conditions an electric current may be passed through the assembly using contacts 34 and 36 which, in the case of a vehicle windscreen washer, would be connected by suitable connecting means including wiring assemblies 50, 52 to the vehicle battery. The current heats the assembly by virtue of a resistive heating effect within the body 11. The exact nature of the material of which body 11 is composed may be chosen according to the resistance required in a particular 8 application. As the assembly's temperature rises towards the desired level, an appropriately chosen thermistor 25 reduces the current through body 11 and hence prevents overheating, while preventing ice from blocking the channel 15 or nozzle opening 18.

1 9

Claims

1. A nozzle assembly suitable for use in projecting a fluid spray, comprising a nozzle portion including a body of electrically conductive material having a.channel through which fluid may be supplied to a nozzle opening in use, a connector portion adapted to mate with the body, and electrical contacts mounted in the assembly to engage the body at spaced locations whereby an electrical current may be passed through the body.

2. An assembly according to Claim 1 wherein the body comprises a sleeve portion adapted to slidingly receive the connector portion in mating engagement with the body.

3. An assembly according to either one of Claims 1 and 2 wherein the connector portion comprises a conduit adapted to cooperate with the channel when the body and connector portion are mated whereby to supply fluid to the channel..

4. An assembly according to Claim 3 wherein the conduit comprises a pipe portion projecting from the connector portion, adapted to be coupled to a hose f or supply ot f luid to the conduit.

1

5. An assembly according to any one of the preceding claims comprising temperature controlling means adapted to-regulate the current flow through the body to maintain the body at a desired temperature.

6. An assembly according to Claim 5 wherein the temperature controlling means includes a thermistor.

7. An assembly according to either one of Claims 5 and 6 wherein the temperature controlling means is positioned adjacent the body whereby to sense the temperature of the body and to regulate the current flowing in the body dependent on the temperature sensed.

8. An assembly according to any one of the preceding claims wherein the connector portion comprises locating means adapted to position at least one of said contacts for engagement with the body.

9. An assembly according to Claim 8 wherein the body comprises a passage in which an electrical contact positioned by the locating means is adapted to be slidingly received when the connector portion is moved into mating engagement with the body.

10. An assembly according to any one of the preceding claims wherein the body comprises a pocket in which one of said contacts is retained, and the connector portion comprises 1 1..

11 support means mounting electrical connecting means in position to engage and make electrical connection with a contact retained in said pocket when the connector portion and body are moved into mating engagement.

11. An assembly according to any one of the preceding claims wherein the body is moulded from an electrically conductive plastics material.

12. A nozzle assembly constructed arranged and adapted to operate substantially as hereinbefore described with reference to the accompanying drawings.

13. A body suitable for use in an assembly according to any one of the preceding claims moulded from an electrically conductive plastics material.

Published 1991 atThe Patent 0171ce. State House. 66/71 High Holborn, LondunWC I R47?. Further copies maybe obtained from Sales Bramb, Unit 6, Nine Mile Point Cwmfelinfacb, Cross Keys. Newport, NPI 7HZ. Printed by Multiplex techniques ltd. St Mary Cray. Kent.