WO2005047070A1

WO2005047070A1 - Vehicle defrosting

Info

Publication number: WO2005047070A1
Application number: PCT/GB2004/004678
Authority: WO
Inventors: Cathy Bye
Original assignee: Nissan Technical Centre Europe Ltd
Priority date: 2003-11-07
Filing date: 2004-11-05
Publication date: 2005-05-26
Also published as: GB2408671A; GB0325998D0; GB0424461D0

Abstract

A vehicle defrosting apparatus (10) comprises a glove (11) having a pouch (20) for containment of a heatable liquid, compound or material (22) and adapted for heating by application of heated air from the vehicle engine. In use, the user retrieves the glove from a compartment in the vehicle and applies the glove to any surface covered by ice or frost. The heat from the liquid, compound or material serves to melt the ice on the surfaces.

Description

VEHICLE DEFROSTING

The present invention relates to vehicle defrosting and particularly, but not exclusively, to a method and apparatus for defrosting the front and rear windscreens and the side windows of a vehicle such as an automobile.

It is a common problem for vehicle owners that, during cold weather, the front and rear windscreens, the side windows and other glazed areas of the vehicle may become frosted. In particularly cold weather, such glazing can become covered in a layer of ice which is sufficiently thick to obscure visibility therethrough. In most cases, the vehicle cannot be driven until the layer of ice is removed.

There are a number of well known devices, on general sale, for effecting the removal of a layer of ice from vehicle glazing. For example, one device, conventionally known as an ice scraper, comprises a rigid body having a handle for grasping by the user and an elongate, laterally directed blade which can be pressed onto the glazing in order to scrape off the layer of ice.

Whilst such devices are generally cheap and simple to manufacture, they are inconvenient, uncomfortable and time consuming to use. Moreover, they are less effective at removing thick layers of ice, frequently leaving behind a smeared residue.

Also known for removing layers of ice from vehicle glazing are pressurised cans of anti-icing spray. These aerosol-based cans contain an anti-freeze liquid which has a freezing point well below 0°C. The liquid is sprayed onto the ice- covered glazing which causes the ice to melt.

Again, these devices are simple and cheap to produce and are relatively easy to use. However, they suffer numerous drawbacks including the inherent danger presented by pressurised containers, the damaging effect of the anti-freeze liquid on vehicle paintwork and the unpleasant odour of the liquid which can easily be transferred onto the user's body or clothes.

Vehicle manufacturers have attempted to alleviate this problem for owners by providing on-board systems which allow the ice to be melted relatively quickly after vehicle start up. In most cases, these systems utilise the conventional vehicle heater to blow warm air over the inside of the glazing, the heat being conducted through the glazing thereby to melt the ice. In other, more sophisticated systems, the glazing is provided with conductive elements laminated into the glazing material which generate heat when an electric current is passed therethrough.

Both types of system usually require the vehicle engine to be started in order to operate correctly and efficiently, in the first case because the engine needs to be warmed sufficiently to generate the heated air and in the second case owing to the level of current needed to heat the conductive elements.

It is an aim of the present invention to provide a method and apparatus for removing a layer of ice from vehicle glazing which is both inexpensive and convenient to use and which addresses some or all of the problems associated with the prior art devices.

According to one aspect of the present invention, therefore, there is provided an apparatus for defrosting a vehicle comprising glove means arranged for insertion of a user's hand therein, the glove means having pouch means containing a heatable liquid, compound or material and adapted for heating by application of heated air from the vehicle engine.

In one embodiment, the pouch means contains a liquid solution such as water. In one embodiment, the pouch means contains a gelatinous compound. In one embodiment, the pouch means contains an aqueous, supercoolable salt solution capable of retaining heat at a relatively low temperature and selectively activatable to cause an increase in temperature thereof. The supercoolable salt solution may comprise sodium acetate, calcium nitrate tetrahydrate or the like.

The glove means may have a back surface and a palm surface. The pouch means may be disposed on or adjacent the palm surface of the glove means. The pouch means may be formed from the same or a different material from the glove means. In one embodiment, the outer surface of the pouch means is formed from a material having a high thermal conductivity. The palm surface of the glove means may be formed from a material having a low thermal conductivity.

The pouch means may be integral with the glove means or may be formed separately from the glove means and attached thereto.

In one embodiment, the pouch means is sealed thereby to contain the heatable liquid, compound or material. In one embodiment, the pouch means is provided with an opening at one end thereof so that a separate, sealed container or pack containing the heatable liquid, compound or material may be inserted therein.

In one embodiment, the device may be placed in or adjacent to a heating device, such as a conventional oven, microwave oven or radiator, so as to apply heat to the heatable solution. In one embodiment, the vehicle is provided with heating means for heating the glove means. The heating means may comprise a compartment arranged to be supplied with hot air from the vehicle engine. Alternatively, the heating means may comprise an electric heating element.

According to another aspect of the invention there is provided a vehicle having heating means for heating an apparatus according to the first aspect of the invention. The heating means may comprise a compartment arranged to be supplied with hot air from the vehicle engine. The compartment may comprise the vehicle glove box. Alternatively, the compartment may comprise a separate compartment within the vehicle glove box or elsewhere in the vehicle cabin.

The vehicle may comprise means for selectively applying heated air from the vehicle to the compartment thereby to heat the apparatus, in use. Alternatively, or in addition, the heating means may include an electric heating element.

The vehicle may comprise means for applying heat to the apparatus for a predetermined period of time and for terminating heat application to the apparatus after the predetermined time.

According to a further aspect of the invention, there is provided a method of defrosting a vehicle, the method comprising heating a device according to the first aspect of the invention, inserting a hand into the device and applying the device to the vehicle thereby to melt the ice formed thereon.

According to a still further aspect of the invention, there is provided a method of defrosting a vehicle, the method comprising retrieving a substantially fully heated apparatus of the type according to the first aspect of the invention from a compartment in the vehicle, inserting a hand into the device and applying the device to the vehicle thereby to melt ice formed thereon.

The method may comprise the step of, after use of the apparatus, placing the apparatus in a compartment within the vehicle and selectively applying hot air from the vehicle engine to the compartment thereby to the heat the apparatus for further use. The present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a underside view of a device according to one aspect of the invention; and

Figure 2 is a cross section through the device of Figure 1 in side elevation.

Referring firstly to Figure 1, a form of device according to the invention is shown generally at 10. The device 10 comprises a glove 11, generally conventional in form, having a rear or back surface 12 and a front or palm surface 14. An elasticised wrist band 16 is provided at one end of the glove 11 and defines an opening for insertion of a user's hand. In the illustrated embodiment, the glove 11 is shown in the form of a mitten having a division 15 for the user's thumb and only a single partition or division 17 for the user's fingers.

A pouch 20 is disposed on the outside of the palm surface 14 of the glove within which a heatable material 22 is contained. The pouch 20 may be formed integrally with the palm surface 14 of the glove 10 or, as illustrated, may comprise an outer skin which is attached or fixed to the palm surface 14 of the glove, for example by means of stitching, to define an enclosure or container for the heatable material 22. In the illustrated embodiment, the palm surface 14 of the glove defines the rear surface or wall of the pouch 20.

In the preferred embodiment, the material 22 comprises an aqueous, supercoolable salt solution such as calcium nitrate tetrahydrate or, preferably, sodium acetate. In one embodiment, the material is food grade sodium acetate which is completely non toxic. Materials of this type have ideal thermal characteristics in that heat applied to the solution is absorbed without significantly raising the temperature of the solution. Activation of the solution produces a highly exothermic reaction which causes the solution to crystallise and release a significant amount of stored energy as heat. The crystallised salt can be returned to solution by simply raising its temperature above the temperature evolved by activation of the exothermic reaction, i.e. above the crystallisation temperature. For many materials, the crystallisation temperature is generally within the range of 100- 130 degrees Fahrenheit.

Activation of the solution can be achieved by generating a sudden deformation or local compression of the solution so as to initiate crystallisation.

Operation of the device 10 is as follows: firstly, the glove 11 or, more particularly, the solution 22 within the pouch 20, is heated using any appropriate heating device. This can be achieved by means of a conventional heating or cooking apparatus such as a conventional oven or microwave oven, within which the glove 11 is placed, or by placing the glove 11 against a radiator or other heater.

The heat generated by the heating device is absorbed by the salt solution 22 although, as described above, the temperature of the solution remains substantially constant indefinitely. The glove 11 can thereafter be stored in an appropriate storage compartment within the vehicle, such as the vehicle glove box, ready for use when desired.

In the event that cold weather causes frosting of the vehicle windows or front and rear windscreen, the user can, without recourse to starting the vehicle, retrieve the glove 11 from the storage compartment for use. After inserting a hand into the glove 11, the user then forcibly brings the glove, palm downwardly, into contact with the vehicle. This may be achieved, for example, by sharply striking the vehicle with the palm of the glove 11 so that the pouch 20 containing the salt solution 22 is suddenly compressed between the user's hand and the vehicle. This abrupt contact of the glove 10 with the vehicle causes a sudden deformation and local compression of the solution 22 within the pouch 20 which is sufficient to initiate crystallisation of the solution 22, as described above.

Thereafter, crystallisation of the salt solution 22 results in a highly exothermic reaction which releases the energy stored in the solution in the form of heat. This heat is conducted through the outer surface 24 of the pouch, the temperature of which therefore rises. On contact with the frosted glazing, the high temperature of the outer surface of the pouch causes the layer of ice to rapidly melt.

Thus, by wiping the glove 11 over the vehicle glazing, in a palm-down orientation such that the outer surface 24 of the pouch 20 is in contact with the glazing, the layer of ice can be rapidly melted and, if desired, wiped from the glazing by using a cloth or by activation of the vehicle window wipers. Once the layer of ice has been removed from the vehicle glazing, the glove can be reheated to a temperature in excess of the melting point of the salt solution to completely liquefy it.

Finally, the solution is again supercooled, by application of heat above the crystallisation temperature of the solution, and the glove 11 can then be returned to the storage compartment of the vehicle.

It will be appreciated that the above-described embodiment is given by way of example only and that various modifications and/or improvements can be made to the invention. For example, although in the illustrated embodiment the glove 11 is shown as a mitten-type glove, a conventional glove having separate divisions for thumb and individual fingers can be used, as can a ~frngerless- type" glove.

The pouch 20 can be formed integrally with the glove 11 or as a separate compartment attached to the palm surface 14 thereof. In this case, the pouch 20 could be completely sealed, having a front and rear surface within which the solution 22 is contained.

Alternatively, the pouch 20 maybe formed of a single skin of material attached to the palm surface 14 of the glove and may be open-ended to define an aperture within which a self-contained pack of the solution can be inserted. This embodiment allows the replacing of the salt solution 22 by replacement of the self-contained pack, for example in the event that the solution loses efficiency.

The material from which the pouch 20 is formed maybe selected as desired. However, preferably the material used has a high thermal conductivity to allow the heat generated by the solution 22 to be transferred therethrough, such that it can be applied to the vehicle glazing with minimal losses. On the other hand, the glove 10, or at least the palm surface 14 thereof, may be made of a material having a low thermal conductivity so that the high temperature generated by the crystallising salt solution 22 following activation is not conducted through to the user's hand thereby causing discomfort or injury.

The use of a supercoolable salt solution is not essential. Other materials, solutions or compounds could be used if desired. In a most basic embodiment, the pouch 20 could contain water which can be heated and the glove 11 then applied to the vehicle as described above. Preferably, however, the material is able to absorb and store energy for an indefinite period of time and then selectively release the energy in the form of heat. Where such a supercoolable solution is employed, however, it may be necessary to include within the pouch 20 an activator, such as that described in US4460546 or US6416309, in order to facilitate activation of the solution.

Heating of the glove 11 can be achieved using any suitable heating device. For example, placement of the glove 11 in a microwave oven or conventional oven can achieve the desired effect. Preferably, however, the glove 11 is adapted for heating through the application of heated air and the vehicle maybe provided with an apparatus for heating the glove to the required temperature thereby to return the solution to its supercooled state.

For example, in one embodiment (not shown) the vehicle is provided with a compartment or enclosure, possibly defined within the glove box of the vehicle, which is supplied with a flow of hot air from the vehicle's engine. A conduit forming part of the vehicle heating and ventilation control (HVAC) system is connected to the compartment and is arranged to supply air, heated by the engine and/or exhaust, thereto. Thus, once the glove 11 has been used, it can be placed into the compartment and heated by air from the vehicle engine. The glove will therefore be ready to use for the next journey of the vehicle.

Since it is relatively straightforward to determine the amount of heat required to fully recharge the solution and return it to its supercooled state, the compartment and/or the HVAC system may include means for selectively terminating the flow of heated air to the compartment after a length of time which is determined to be sufficient to full recharge the solution in the glove. Such means may comprise a mechanically or electrically actuable valve or flap which is operable to selectively divert the heated into or away from the compartment. In this manner, once the solution is heated to a sufficient level, or to its maximum extent, the valve or flap may be actuated automatically to terminate the flow of heated air into the compartment and divert it, for example, into the vehicle cabin. This ensures that heated air is not wasted by being conducted to a fully heated solution.

Alternatively, or in addition, one or more electric heating elements can be provided within the compartment which are connected to the vehicle battery. Current from the battery is passed through the elements which causes heating thereof. The glove 11 can thus be placed adjacent the elements and heated therefrom.

On short vehicle journeys, the engine may not run for a duration sufficient to fully heat the solution. For example, it often takes between five and fifteen minutes to reach normal engine operating temperature. This may equate to a journey of between approximately 3 and 10 miles. For journeys of this length, there may not be sufficient time to fully heat the solution with the result that when the user later comes to use the glove, it is not sufficiently heated to operate correctly.

In one embodiment, therefore, the electric heater may be arranged to continue to heat the glove after the vehicle ignition is turned off if the length of time that the engine has been operating is less than a predetermined length of time. The heater may continue to heat the glove and solution for a time sufficient to ensure full recharging of the solution.

The compartment may constitute a separate compartment within the glove box of the vehicle, and may be thermally insulated so as to maximise heat transfer efficiency between the HVAC system and the glove.

Application of hot air to the glove in order to heat the solution following use also has the beneficial effect of drying the material of the glove which will necessarily have become wet or damp during use to melt the frozen layer on the vehicle glazing.

Claims

1. An apparatus for defrosting a vehicle, the apparatus comprising glove means arranged for insertion of a user's hand therein, the glove means having pouch means containing a heatable liquid, compound or material and adapted for heating by application of heated air from the vehicle engine.

2. An apparatus as claimed in claim 1 wherein the pouch means contains an aqueous, supercoolable salt solution capable of retaining heat at a relatively low temperature and selectively activatable to cause an increase in temperature thereof.

3. An apparatus as claimed in claim 2 wherein the solution comprises sodium acetate or calcium nitrate tetrahydrate.

4. An apparatus as claimed in claim 1, 2 or 3 wherein the glove means has a back surface and a palm surface.

5. An apparatus as claimed in claim 4 wherein the pouch means is disposed on or adjacent the palm surface of the glove means.

6. An apparatus as claimed in any preceding claim wherein the pouch means is formed from a different material from the glove means.

7. An apparatus as claimed in any preceding claim wherein an outer surface of the pouch means is formed from a material having a high thermal conductivity.

8. An apparatus as claimed in any preceding claim wherein the palm surface of the glove means is formed from a material having a low thermal conductivity.

9. An apparatus as claimed in any preceding claim wherein the pouch means is sealed thereby to contain the heatable liquid, compound or material.

10. An apparatus as claimed in any of claims 1 to 9 wherein the pouch means is provided with an opening at one end thereof for insertion of a separate, sealed container or pack containing the heatable liquid, compound or material

11. A vehicle having heating means for heating an apparatus as claimed in any- preceding claim.

12. A vehicle as claimed in claim 11 wherein the heating means comprises a compartment arranged to be supplied with hot air from the vehicle engine.

13. A vehicle as claimed in claim 12 wherein the compartment comprises the vehicle glove box.

14. A vehicle as claimed in claim 12 wherein the compartment comprises a separate compartment within the vehicle glove box.

15. A vehicle as claimed in claim 14 comprising means for selectively applying heated air from the vehicle to the compartment thereby to heat the apparatus, in use.

16. A vehicle as claimed in claim 11 wherein the heating means comprises an electric heating element.

17. A vehicle as claimed in any of claims 11 to 16 comprising means for applying heat to the apparatus for a predetermined period of time and for terminating heat application to the apparatus after the predetermined time.

18. A method of defrosting a vehicle, the method comprising heating an apparatus according to any of claims 1 to 10, inserting a hand into the device and applying the device to the vehicle thereby to melt ice formed thereon.

19. A method of defrosting a vehicle, the method comprising retrieving a substantially fully heated apparatus of the type described in any of claims 1 to 10 from a compartment in the vehicle, inserting a hand into the device and applying the device to the vehicle thereby to melt ice formed thereon.

20. A method as claimed in claim 18 or claim 19 comprising the step of, after use of the apparatus, placing the apparatus in a compartment within the vehicle and selectively applying hot air from the vehicle engine to the compartment thereby to the heat the apparatus for further use.