GB2297710A

GB2297710A - A heated scraper

Info

Publication number: GB2297710A
Application number: GB9502685A
Authority: GB
Inventors: Albert Edward Barker; Brian Thomas Webb
Original assignee: GLOBAL DOMESTIC PROD Ltd
Current assignee: GLOBAL DOMESTIC PROD Ltd
Priority date: 1995-02-11
Filing date: 1995-02-11
Publication date: 1996-08-14
Anticipated expiration: 2015-02-11
Also published as: GB9502685D0; GB2297710B

Abstract

A heated scraper for removing paint or other substances from a surface includes a blade 1 having a scraping edge, means such as an electrical resistance element 3 for heating the blade and a thermally conducting mass 2 attached thereto, and a handle 4 incorporating a switch 5 to connect a power supply 7 to the element 3. Sufficient heat, which may be variable, is transmitted to the scraping edge of the blade 1 to enable softening of paint and there may be included an adjustment device where the operator can select a temperature appropriate to the nature of the work in hand. An alternative to the electrical heating element is a concealed gas flame adapted to impinge upon the blade 1 or the mass 2 in which case the handle 4 incorporates a gas cylinder and a piezo-electric ignition device.

Description

A HEATED SCRAPER THIS INVENTION concerns a heated scraper preferably, though not exclusively, for removal of hardened paint from a surface.

Removal of paint and other coating materials is sometimes carried out by mechanical means such as sandpaper or a simple bladed device but this method requires considerable physical work, and the mechanical effort imposed upon the paint can inadvertently damage the substrate surface beneath.

A further method is by the use of a chemical substance which softens the paint or other coating and destroys the bond between the coating and the substrate surface. The use of such substances which may be caustic, requires considerable care and experience so as to avoid injury to the operator or damage to adjacent items of furniture, fabrics or other decorative finishes.

Another disadvantage of chemically aided removal substances is that all traces thereof must be removed prior to re-painting of the surface in order to avoid dissolving of the new paint.

The most common method of removing paint and other such substances is by the use of heat and typically includes the use of a blow lamp which produces a flame by means of a liquid of gaseous fuel, the flame being used to soften the paint and loosen the bond prior to mechanical scraping. A disadvantage of this method is that considerable care is required to avoid overheating the substrate material such as softwood, which can cause charring, and the risk of damaging adjacent surfaces such as window glass. Methods involving burning and scraping require the operator to use both hands and this presents a further difficulty when operating, for example, at the top of a ladder.

According to the present invention there is provided a heated scraper comprising a blade, means for heating the blade to a temperature which will soften the material such as paint to be removed, a handle to enable the scraper to be used by hand, and a power supply.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings, in which: Fig. 1 is a plan view of a heated scraper made in accordance with the invention; and Fig. 2 is a side view thereof.

A heated scraper for removing paint, for example, from a wooden surface includes a metallic blade 1 preferably but not necessarily of mild steel, a thermally conductive mass 2 attached to and occupying substantially the entire area of the blade 1, a heating means 3 such as an electrical resistance element, and a handle 4 which may incorporate a switch 5 and a control circuit 6 supplied electrically by means of a power lead 7.

The blade 1 may be of any suitable shape to assist in the process of scraping away paint or other material and may be in the form of an interchangeable unit thus providing alternative blade shape selections appropriate to the nature of the work in hand.

The blade must be capable of transmitting heat to the paint at the point of contact between the surface of the paint and the blade and, provide an edge suitable for enabling paint to be scraped away.

The electrical element 3 may be in the form of an insulated heating element arranged in direct contact with the blade or with the thermally conductive mass 2 attached thereto. Alternatively, the heating element may be constructed by means of deposited element technology whereby a high resistance electrically conductive path is printed or otherwise deposited onto the blade surface so as to form the means of providing a heating element. A heating element constructed in this way may be applied over a dielectric layer directly upon the blade or alternatively upon a thermally conductive mass attached to the blade, and may be on one or both surfaces of the blade. The material of the blade may be selected such that it will dissipate its heat not only by conduction at the point of contact but also, or alternatively, by radiation or convection onto the surface of the material to be heated.

The operating temperature of the device will be selected according to the amount of heat required to carry out the intended work. This may be predetermined by design parameters and may be thermostatically controlled. Alternatively, the heat may be variable and set by the operator according to the work in hand, i.e.

particularly difficult paint to remove could be encouraged by increasing the temperature.

The device may incorporate audio visual indicators to signify the status of the device i.e. to indicate when it is either switched on or has attained the required temperature.

Preferably, the power supply cable should be of a highly flexible nature since the device in use will be subject to repeated movements back and forth and so the cable should be protected against wear at the point of attachment to the device.

It is not intended to limit the invention to the above example only. For example, the blade may be heated by nonelectrical means such as a concealed gas flame adaptable to impinge upon the blade within the thermally conductive mass 2, the handle 4 incorporating a gas cylinder and, preferably, a piezo-electric ignition device to ignite the gas when required. The connection of the handle to the blade assembly would include a flow control valve to regulate the gas flow. In this manner, the device may be entirely selfcontained, requiring no electrical power cable for its operation. Once again, audio visual means should be included to provide an indication when the device is operating and hot.

Claims

1. A heated scraper comprising a blade having a scraping edge, means for heating the blade to a temperature which will soften the material such as paint to be removed, a handle to enable the scraper to be used by hand, and a power supply.

2. A heated scraper according to Claim 1, including a thermally conductive mass attached to and occupying substantially the entire area of the blade.

3. A heated scraper according to Claim 1 or Claim 2, wherein the heating means comprises an electrical resistance element, and the handle includes a switch to connect the power supply to the element.

4. A heated scraper according to any of Claims 1 to 3, wherein the blade is removably attached with respect to the handle and interchangeable with other blades to provide alternative blade shape selection.

5. A heated scraper according to Claim 3, wherein the electrical resistance element is an insulated heating element arranged in direct contact with the blade.

6. A heated scraper according to Claim 3, wherein the electrical resistance element is constructed by means of deposited element technology and includes a high resistance electrically conductive path printed or otherwise deposited over a dielectric layer deposited directly onto the blade surface.

7. A heated scraper according to any preceding claim, wherein the material of the blade is such that it will dissipate its heat not only by conduction at the point of contact but also by radiation or convection onto the surface of the material to be removed.

8. A heated scraper according to any preceding claim, including adjustment means to vary the heat attained by the blade.

9. A heated scraper according to any preceding claim, including a thermostat to maintain a substantially constant heat in the blade.

10. A heated scraper according to any preceding claim, including audio or visual indicator means to signify the operational status of the scraper.

11. A heated scraper according to Claim 1 or Claim 2, wherein the blade is heated by means producing a concealed gas flame adapted to impinge upon the blade, the handle incorporating a gas cylinder and a piezo-electric ignition device to ignite the gas.

12. A heated scraper according to Claim 11, wherein connection of the handle to the blade includes a flow control valve to regulate the gas flow.

13. A heated scraper substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawings.