WO2018091932A1

WO2018091932A1 - Apparatus and method for abrading or slicing-off a high point of a surface

Info

Publication number: WO2018091932A1
Application number: PCT/GB2017/053496
Authority: WO
Inventors: Alan Wilkinson
Original assignee: Alan Wilkinson
Priority date: 2016-11-21
Filing date: 2017-11-21
Publication date: 2018-05-24
Also published as: GB2556102A; GB201619623D0

Abstract

A stencil (1) for finishing a vehicle surface, the stencil (1) comprising a body with a plurality of apertures (2) for positioning over the vehicle surface to be repaired or abraded, the body having areas (3) of reduced thickness surrounding the apertures (2).

Description

APPARATUS AND METHOD FOR ABRADING OR SLICING-OFF A HIGH POINT OF A SURFACE

The present invention relates to a stencil for finishing a vehicle surface, and a method of manufacture of the stencil, for example for use in the vehicle re-finishing trade.

BACKGROUND TO THE INVENTION

When a technician is performing a repair, for example, abrading excess material after filling a stone chip or scratch with paint, or if they need to remove a run as a result of incorrect lacquer application, the area surrounding the area to be abraded must be protected if damage is to be avoided. This is commonly done by applying adhesive masking tape. Disadvantages of this are that the tape is easily abraded by the abrasive material employed. It is also too thick to be near flush with the surface so that when the abrasive is passed over the tape, the area under repair is still considerably higher than the remaining surface. Consequently, the repair must be finished without masking tape if a flush repair is to be achieved, increasing the risk of damage to the surrounding area. A protective stencil can be used, having the properties of being very thin whilst being resistant to abrasive materials. A high spot as previously mentioned may be removed by selecting a stencil with a suitable size and shape of hole, and placing this hole over the high spot (the stencil maybe taped into position or hand-held against the surface to be worked on). The high spot is then exposed and slicing the excess material is possible with a very sharp blade e.g. a one-sided razor blade over the stencil held at near to horizontal to the stencil. This can then be abraded either by hand with an abrasive wrapped around a suitable sanding block, or by means of a sanding machine. The result will be that the material within the selected hole in the stencil will stand as high as the thickness of the stencil, if a hard block or backing plate is employed. This may then be finished with a fine abrasive once the stencil has been removed, so minimizing risk of damage to the surrounding surface.

If a softer block or backing pad is employed, the area inside the stencil shape will be abraded and can be feathered by placing successively larger sized shapes over the repair spot and abrading with successively finer abrasives.

A stencil of this type is disclosed in granted UK patent application GB2485594 entitled Shim-Mask stencil which proposes a stencil made of stainless steel with a thickness of between 0.03 mm and 0.05 mm.

However, a thickness of 0.05mm means that when the stencil is removed after abrading, the high point is still 0.05mm above the surface and so further abrasion is necessary to bring this level flush with the surface. In practice, a stencil thickness of less than 0.05mm in stainless steel is dangerous to use without the use of protective gloves because of the risk of users cutting their fingers on the perimeter edges of the stencil, and particularly on the 90° corners.

It is an object of the present invention to provide an improved stencil and method, which reduces these problems.

STATEMENT OF INVENTION

According to a first aspect of the invention, there is provided a stencil for finishing a vehicle surface, the stencil comprising a body with a plurality of apertures for positioning over the vehicle surface to be repaired or abraded, the body having areas of reduced thickness surrounding the apertures.

This allows an initial step of abrading or slicing off a high point on the surface to be closer to the vehicle surface than the thickness of the stencil. As a result, less final abrasion is required to reduce the high point to be flush with the surface.

The apertures and/or the areas of reduced thickness may be formed by chemical etching.

Each area or region of reduced thickness may have a perimeter which is spaced from its respective aperture by a distance of 3mm to 6mm. Each area of reduced thickness may have a perimeter which is spaced from its respective aperture by a constant distance. In other words, the reduced thickness around each aperture may have a constant width. It may have a variable width.

The body may have a thickness in the range 0.03mm to 0.05mm. Each area may have a reduced thickness of at least 0.01mm. Preferably, the reduced thickness is in the range 0.01mm to 0.025mm.

The body may be made of a material which is resistant to abrasion and/or oxidation. The body may comprise at least one of the following: stainless steel; stainless steel shim; hard quality stainless steel shim. The body may have rounded corners for safety.

According to a second aspect of the invention, there is provided a process of manufacturing a stencil for finishing a vehicle, the process comprising the steps of: a) providing a body for a stencil;

b) performing an etching process on the body which creates a plurality of apertures through the body, forming a stencil, and creates areas of reduced thickness surrounding each aperture.

The apertures can be etched at the same time as the areas of reduced thickness. Alternatively, the apertures may be etched in a separate step to etching the areas of reduced thickness. For example, this may involve performing a first etching process on the body to create a plurality of apertures through the body, forming a stencil; and then performing a second etching process on the body on areas surrounding each aperture, reducing the thickness of the body in those areas.

In another alternative, the apertures may be etched after the areas of reduced thickness are etched. In that case, first a plurality of regions of reduced thickness would be formed on the body. Optionally, a protective layer can be applied to the regions of reduced thickness, for preventing further etching of those areas of reduced thickness. Apertures can subsequently be created within each of the regions of reduced thickness by etching. The apertures would thus be formed inset from the edge or perimeter of each region. Although the intermediary product would be different to etching the apertures first, the final product would be substantially the same. Steps (b) and/or (c) may involve chemical etching processes. Each area in step (c) may have a perimeter which is spaced from its respective aperture by a distance of 3mm to 6mm. Each area in step (c) may have a perimeter which is spaced from its respective aperture by a constant distance. In other words, the reduced thickness around each aperture may have a constant width. It may have a variable width.

The body may have a thickness in the range 0.03mm to 0.05mm. Each area in step (c) may have a reduced thickness is in the range 0.01mm to 0.025mm.

According to a third aspect of the invention, there is provided an improved method of abrading or slicing-off a high point of a surface, comprising the steps of:

a) providing a masking stencil comprising a sheet of flexible, abrasion-resistant material, the masking stencil having a plurality of apertures formed by chemical etching, a perimeter region surrounding each aperture being further etched and having a reduced thickness relative to the sheet;

b) locating the stencil with the high point being positioned within a selected aperture; and

c) passing a blade or abrasive tool over the stencil, until the high point is reduced to the height of the stencil thickness.

The masking stencil may be made of stainless steel. The sheet may have rounded corners. The perimeter region around each aperture may extend from each aperture by a distance in the range 3mm to 6mm.

The body of the stencil may have a thickness in the range 0.03mm to 0.05mm. The perimeter region may have a reduced thickness in the range 0.01mm and 0.025mm. According to a fourth aspect of the present invention, there is provided an improved method of abrading or slicing-off a high point of a surface, comprising the steps of a) providing a stencil comprising a sheet of flexible, abrasion-resistant stainless steel, the masking stencil having a plurality of apertures therein, the apertures having been formed by chemical etching and the stencil body having a thickness of 0.03mm to 0.05mm and having rounded corners to minimise danger to users, and where the perimeter area surrounding each aperture is submitted to a further etching process which reduces the thickness to between 0.01mm and 0.025mm,

b) locating the stencil with the high point being positioned within a selected aperture, and

The present invention therefore effectively increases the efficiency of the process as now when the stencil is removed, the high point is only 0.01mm to 0.025mm above the surrounding area meaning that less final abrasion is required to reduce the high point to be flush with the surface, so reducing the work required as well as the risk of rubbing through the surrounding area which is the objective of using an abrasion resistant stencil.

The reason that the current invention lies perfectly flat is that stencil holes in a very abrasion-resistant material are chemically etched so no burring of edges occurs.

The method may include the step of (d) locating a larger sized shape, having a larger aperture than the first aperture, with the reduced high point being positioned within the larger aperture. The method may further include the step of (e) passing a blade or abrasive tool over the larger sized shape. The larger sized shape may be part of the same stencil, or may be a separate object.

An abrasive may be used in steps (c) and (e). Preferably a finer abrasive is used in step (e) than in step (c). The apertures through the stencil are preferably smaller than the dimensions of the blade or abrasive tool.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made by way of example only to the accompanying drawings, in which:

Figure 1 shows a front view of a stencil according to the first aspect of the invention. DESCRIPTION OF PREFERRED EMBODIMENT

A preferred embodiment of the stencil included in the method will now be given.

Referring to Figure 1, a stencil 1 for finishing a vehicle is shown. The stencil 1 has a body which is manufactured from hard quality stainless steel shim in this embodiment. Using stainless steel means that the stencil is highly durable to abrasion. This means that it does not wear away quickly, and protects a vehicle surface that does not need finishing. It also means that the stencil is not prone to oxidation or rusting, which might otherwise affect positioning on the vehicle surface. This allows the stencil to be used many times.

The stencil 1 is 0.05mm thick in this embodiment. The stencil 1 is 12cm long and 12cm wide in this embodiment. The body of the stencil 1 has rounded corners.

A plurality of apertures or holes 2 are provided through the stencil 1. Four holes are provided in this embodiment. The holes 2 are designed to fit over and around typical spot repairs, keeping them exposed for repair during use. For example, typical spot repairs can include: lacquer runs, imperfections and paint-filled chips, or scratches. The body of the stencil 1 protects portions of a vehicle which do not require repair from being damaged.

Starting with a stencil body, the holes 2 are created by a process that ensures that edges of the holes 2 are flush with the stencil body. For example, an etching process can be used to create etched holes 2. In this embodiment, a chemical etching process is used. An area 3 around each hole 2 is then subjected to a further process which reduces the thickness of the stencil body. For example, a second etching process can be used. In this embodiment, chemical etching is used again.

After the second process is performed, each area 3 of the stencil body is between 0.01mm thick and 0.025mm thick. In this embodiment, the perimeter of the area 3 around each hole is 3mm to 6mm from its respective hole 2. Each area 3 has a constant width from the edge of its associated hole 2.

The dimensions of each hole 2 are calculated and chosen to prevent a repair tool from making contact with the surface of the vehicle next to the spot to be repaired. This is because when the repair tool is held horizontal to that surface during use, the repair tool is unable to fit completely inside the hole 2. Examples of such repair tools include an abrasive block, a sanding machine pad, or a blade. Different shapes and sizes of holes are provided. In this embodiment, the holes 2 include: a circular hole of a first diameter; a second circular hole of a second larger diameter; an elongate slot of a first width; and a second elongate slot of a second larger width. It will be appreciated that other sizes and shapes of holes can be provided in alternate embodiments, although the dimensions are still selected to prevent a repair tool from contacting the bulk of the vehicle surface being repaired.

In use, the stencil 1 is located against a vehicle surface. One of the apertures is selected and positioned over a high point that is going to be abraded or sliced off. A blade or abrasive tool is passed over the stencil to reduce the high point to the height of the stencil thickness. Another larger aperture is then selected and positioned over the reduced high point. A blade or abrasive tool is then passed over the stencil to further reduce the high point. Where an abrasive tool is used, the second pass ideally involves a finer abrasive. An alternate description of the stencil would be as follows. Referring to again to Figure 1, a top view of a stencil 1 is shown, manufactured from 0.05mm hard quality stainless steel shim in a sheet measuring 12cm by 12cm with rounded exterior stencil body corners, with holes 2 designed to expose typical spot repairs, namely lacquer runs, imperfections and paint-filled chips or scratches, and created by a process to ensure that edges are flush with stencil body, for example an etching process.

An area surrounding each etched hole 3, for example a 3mm to 6mm perimeter, is subjected to a further etching process which reduces the stencil body thickness to between 0.01mm and 0.025 mm. The etched holes are calculated to be of a dimension that will not allow the abrasive block, sanding machine pad or blade, when held horizontal to the surface, to make contact with the surface to be protected at any point, i.e. the dimensions of the holes are too small to allow the sanding block, machine pad or blade to fit completely inside.

The stainless steel employed to make the stencil offers high durability to the abrasion process so that the surface to be protected is so, prevents the stencil from oxidation, which would affect its uniform positioning on the surface, and allows the stencil to be re-used.

Claims

1. A stencil for finishing a vehicle surface, the stencil comprising a body with a plurality of apertures for positioning over the vehicle surface to be repaired or abraded, the body having areas of reduced thickness surrounding the apertures.

2. A stencil as claimed in claim 1, in which the apertures and/or the areas of reduced thickness are formed by chemical etching.

3. A stencil as claimed in claim 1 or 2, in which each area of reduced thickness has a perimeter which is spaced from its respective aperture by a distance of 3 mm to 6mm.

4. A stencil as claimed in any preceding claim, in which each area of reduced thickness has a perimeter which is spaced from its respective aperture by a constant distance.

5. A stencil as claimed in any preceding claim, in which the body has a thickness in the range 0.03mm to 0.05mm, and each area has a reduced thickness in the range 0.01mm to 0.025mm.

6. A stencil as claimed in any preceding claim, in which the body is made of a material which is resistant to abrasion and/or oxidation.

7. A stencil as claimed in any preceding claim, in which the body comprises at least one of the following: stainless steel; stainless steel shim; hard quality stainless steel shim.

8. A process of manufacturing a stencil for finishing a vehicle, the process comprising the steps of:

a) providing a body for a stencil;

9. A process as claimed in claim 8, in which step (b) comprises:

i) performing a first etching process on the body to create a plurality of apertures through the body, forming a stencil; and ii) performing a second etching process on the body on areas surrounding each aperture, reducing the thickness of the body in those areas;

where steps (i) and (ii) can be performed in either order.

10. A process as claimed in claim 8 or 9, in which steps (b) and/or (c) involve chemical etching processes.

11. A process as claimed in any of claims 8 to 10, in which each area in step (c) has a perimeter which is spaced from its respective aperture by a distance of 3 mm to 6mm.

12. A process as claimed in any of claims 8 to 11, in which each area in step (c) has a perimeter which is spaced from its respective aperture by a constant distance.

13. A process as claimed in any of claims 8 to 12, in which the body has a thickness in the range 0.03mm to 0.05mm, and each area in step (c) has a reduced thickness in the range 0.01mm to 0.025mm.

14. A process as claimed in any of claims 8 to 13, in which the body is made of a material which is resistant to abrasion and/or oxidation.

15. A process as claimed in any of claims 8 to 14, in which the body comprises at least one of the following: stainless steel; stainless steel shim; hard quality stainless steel shim.

16. An improved method of abrading or slicing-off a high point of a surface, comprising the steps of:

a) providing a masking stencil comprising a sheet of flexible, abrasion- resistant material, the masking stencil having a plurality of apertures formed by chemical etching, a perimeter region surrounding each aperture being further etched and having a reduced thickness relative to the sheet; b) locating the stencil with the high point being positioned within a selected aperture; and

17. An improved method of abrading or slicing-off a high point of a surface, comprising the steps of:

a) providing a stencil comprising a sheet of flexible, abrasion-resistant stainless steel with rounded corners, the masking stencil having a plurality of apertures therein, the apertures having been formed by chemical etching and the stencil body having a thickness from 0.03mm to 0.05mm, a perimeter of 3mm to 6mm surrounding each aperture being further etched and having a reduced thickness of between 0.01mm and 0.025mm, b) locating the stencil with the high point being positioned within a selected aperture, and

18. A method of abrading or slicing-off as claimed in claim 17, further comprising the steps of:

d) locating a larger sized shape, having a larger aperture than the first aperture, with the reduced high point being positioned within the larger aperture, and

e) passing a blade or abrasive tool over the larger sized shape.

19. A method of abrading or slicing-off as claimed in claim 18, in which an abrasive is used in steps (c) and (e), and in which a finer abrasive is used in step (e) than in step (c).

20. A method of abrading or slicing-off as claimed in any of claims 17 to 19, in which the apertures through the stencil are smaller than the dimension of the blade or abrasive tool.