GB2261160A - Thawing frozen pipes with electricity - Google Patents

Abstract

The frozen fluid in a plastic pipe (e.g. of a windscreen washer system) is thawed by supplying a source of electrical current (e.g. a vehicle battery) to the fluid by means of conductors 20, 22, to cause a flow of current through the fluid. A metallic sleeve 18 and/or nipple 6 may be provided to effect connection between the fluid and the conductors. A time switch 24 may be provided. <IMAGE>

Description

Title: "Improvements relating to the thawing of frozen pipes" Description of the Invention This invention is concerned with improvements relating to the thawing of frozen pipes, particularly pipes delivering fluid to the windscreen of a vehicle.

It is however to be appreciated that the invention has broader application, and may be utilised in general to assist in the thawing of frozen fluid in pipes.

A conventional windscreen washer system for a vehicle comprises a nipple, secured adjacent to the windscreen, either at the front or the rear, and connected to a supply of washing fluid by a plastic pipe. Conventionally the supply is derived from a container which may be pressurised to deliver fluid from the nipple onto the screen, to enable the screen to be washed by the conventional wipers.

Conventionally the nipple is of metal, or comprises an outlet afforded by a metal sleeve. Additionally, by virtue of the nipple being outside the vehicle, fluid in the nipple and adjacent portion of the connecting pipe tends to freeze in cold weather, despite the addition of anti-freeze, since under static conditions alcohol in the anti-freeze tends to evaporate through the outlet.

According to this invention there is provided a method of thawing a frozen pipe, wherein there is provided adjacent to a plastic section of the pipe two metallic parts, each located in or defining a portion of a flow passage, and providing a potential difference between such metallic parts.

Thus in a plastic flow pipe two spaced metallic tube sections may be provided, across which the potential difference may be applied, enabling current to flow through the frozen liquid in the tube between the metallic tube sections.

Alternatively, the metallic parts may be provided by conductor members which extend at spaced locations though the walls of a plastic section or sections of the pipe, enabling current to flow between the conductors when required.

One of the metallic parts may be provided by an outlet for the fluid.

According to this invention there is also provided a fluid delivery system comprising a plastic pipe, two electrically conductive elements, and means to apply a potential difference between said conductive elements so that current flowing therebetween flows through fluid in the delivery system.

If desired one of the conductive elements may be provided at or adjacent to an outlet for fluid from the delivery system, the other conductive element being provided by a conductive member extending through the wall of the plastic pipe into the interior thereof, or a metallic section of the pipe interposed between adjacent plastic portions.

According to this invention there is also provided a windscreen washer system comprising fluid delivery means comprising an outlet nozzle and a delivery means connected to the outlet nozzle from a supply of washer fluid, comprising conductive members at spaced locations in the fluid flow path, and means to apply a potential difference between said conductive members.

Preferably one conductive member is provided by a metallic tubular member providing a flow passage through which fluid may flow, and if desired the other conductive member may be also so provided. Alternatively said other conductive member may be provided by a member defining an outlet of fluid from the system.

In this manner in the event of freezing of fluid in the vicinity of the outlet member, on application of a potential difference between the two conductive members electric current will flow through the frozen fluid, causing it to melt, allowing flow of fluid from the outlet member onto the windscreen.

If desired there may be a time switch interposed in a circuit by which current is supplied to the conductive members, limiting the application of current to an appropriate period of time, e.g. one minute. Alternatively, since on termination of the melting operation fluid in the delivery pipe will simply commence to be evaporated away, breaking the conductive path between the conductive members, allowing no further current to flow until further fluid is introduced into the flow pipe, a potential difference may be applied across the conductive members without time restriction.

There will now be given a detailed description, to be read with reference to the accompanying drawing, of a de-icing system which has been selected for the purposes of illustrating the invention by way of example.

In the accompanying drawing is a schematic representation showing the application of the invention to the de-icing of a fluid delivery system of a vehicle windscreen washer system.

In accordance with the preferred embodiment an outlet member, in the form of a nipple 6 of metallic material, is secured by a nut 8 to a panel 10 of the vehicle body, so that an outlet passage 12 of the nipple is directed towards the vehicle windscreen. Extending inwardly from the nipple 6 is a stem 14, connected in conventional manner by a plastic tube or pipe 16 to a supply of washing fluid.

Under normal circumstances under cold weather conditions, residual washing fluid in the passage 12, the stem 14 and portions of the pipe 16 adjacent thereto tend more readily to freeze, due in part to the proximity to the exterior of the vehicle, and in part to the tendency for the alcohol component of antifreeze added to the fluid to evaporate through the outlet.

In accordance with the present invention of the metal tube or sleeve 18 is interposed in the plastic pipe 16 adjacent to its outlet end. A source of electric current is connected between the component 18 and the nipple 6 by conductors 20, 22 respectively. Conveniently the conductors 20, 22 are connected to the vehicle battery through a manually operated time switch 24. Thus in the event that fluid within the system is frozen, by setting of the time switch 24 current is caused to flow between the component 18 and 6 for a period of time as determined by the time switch, typically for one minute, causing current to flow through the frozen fluid at the forward region of the pipe 16, in the stem 14 and in the outlet channel 12. Additionally such flow of current will raise the temperature slightly of the tube 18, and of the nipple 6, reducing tendency for refreezing to occur.

Should the switch 24 be operated in the absence of frozen fluid, or the switch 24 to remain activated subsequent to thawing of the frozen fluid, the fluid will simply boil off, being vented through the outlet channel 12, breaking the conductive path between the conductors 20 and 22. Thus, if desired the time switch 24 may be dispensed with, and the conductors 20, 22 may be permanently connected to the battery, preferably through the vehicle ignition system so that the conductors are unpowered when the vehicle is inactive, although under such circumstances the portion 16 of the pipe is preferably of heat resistant material.

The polarity of connection of the conductors 20 and 22 is not material to the operation of the invention, although in practice the conductor 22 will be at earth potential.

It will be appreciated that whilst in the preferred embodiment the use of a nipple 6 of metal is described, in practice the invention may be utilised with a plastic nipple, particularly where the channel 12 is defined by a metallic tubular insert (widely utilised to assist in cleaning of the channel 12), or simply by the conductor 22 extending into the outlet channel 12, where the outlet channel 12 is defined by a plastics component.

Indeed in its broader context the sleeve 18 may be omitted, the conductor 20 extending through the wall of the plastic tube 16.

Conveniently if desired the assembly illustrative in the drawings, comprising the sleeves 18, the pipe 16, the stem 14 and nipple 6 may be moulded in one part, with appropriate metal parts inserted.

If desired an additional sleeve 18# similar to the sleeve 18, may be inserted in the pipe 16 upstream of the sleeve 18, being connected electrically to the conductor 22.

It is to be understood that the invention may be utilised in the de-icing of further fluid delivery systems, such as in household water supplies.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in the terms or means for performing the desired function, or a method or process for attaining the disclosed result, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims (16)

1. A method of thawing a frozen pipe, wherein there is provided adjacent to a plastic section of the pipe two metallic parts, each located in or defining a portion of a flow passage, and providing a potential difference between such metallic parts.

2. A method according to Claim 1 wherein at least one of the metallic parts is provided by a metallic tube section.

3. A method according to one of Claims 1 and 2 wherein at least one of the metallic parts is provided by a conductor member which extends through the wall of a plastic section of the pipe.

4. A method according to any one of the preceding claims wherein one of the metallic parts is provided by an outlet for the fluid.

5. A fluid delivery system comprising a plastic pipe, two electrically conductive elements and means to apply a potential difference between said conductive elements so that current flowing therebetween flows through the fluid in the delivery system.

6. A system according to Claim 5 wherein one of the conductive elements is provided at or adjacent to an outlet for fluid from the delivery system.

7. A system according to Claim 6 wherein the other conductive element is provided by a conductive member extending through the wall of the plastic pipe into the interior thereof.

8. A system according to Claim 6 wherein the other conductive element is provided by a metallic section of the pipe interposed between adjacent nonconductive portions.

9. A windscreen washer system comprising fluid delivery means comprising an outlet nozzle and a delivery means connected to the outlet nozzle from a supply of washer fluid, comprising conductive members at spaced locations, and means to apply a potential difference between said conductive members, such that current flows along said fluid flow path.

10. A windscreen washer system according to Claim 9 wherein one conductive member is provided by a metallic tubular member providing a flow passage through which fluid may flow.

11. A system according to Claim 10 wherein the other conductive member is so provided, or is provided by a conductor element extending into said fluid flow path.

12. A system according to Claim 10 wherein said other conductive member is provided by a member defining an outlet of fluid from the system.

13. A system according to any one of Claims 5 to 12 comprising a time switch interposed in a circuit by which current is supplied to the conductive members.

14. A method of thawing a frozen pipe, when carried out substantially as hereinbefore described with reference to the accompanying drawings.

15. A windscreen washer system constructed and arranged substantially as hereinbefore described with reference to the accompanying drawings.

16. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.