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(11) | EP 2 105 254 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Manual tool for the removal of lime plaster from mural and stone supports |
| (57) A new manual tool (U, V) for the removal of lime plaster comprises a support (1)
on one side of which an active element (2, 6) is applied consisting of a series of
parallel blades (6) slanting both with respect to the surface of the support (1) and
with respect to the lateral edge of the support (1) or consisting of a wire mesh made
of stretched sheet metal (2). On the side of the metal plate constituting the support
(1) opposite the active element (6, 2) there is a handle (4) and supports for the
sensor pads (5b). When said sensor pads (5b) are rotated, the circular foot (5b3)
is moved parallel to the active element (2). A light indicator and/or buzzer is combined
with each sensor pad (5b).
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[0001] The present patent concerns tools for restoration and treatment of wall supports and in particular concerns tools and instruments for the removal of lime plaster.
[0002] Lime plastering is a technique used to whitewash existing wall paintings by applying a layer of lime plaster a few millimetres thick. Lime plastering is performed, and was often performed in the past, mainly to cover existing wall paintings in a particular style no longer in vogue.
[0003] Consequently the lime plaster is usually removed to uncover paintings and frescoes of particular value.
[0004] The lime plaster can be removed mechanically or by using solvents. The use of solvents for removing the lime plaster involves a lengthy operating procedure, the use of costly solvents, protective means for eliminating the vapours of the solvents used.
[0005] The solvents used, suitable for the removal of lime plaster, can modify or negatively affect the pictorial layer to be uncovered, thus defeating the object of said operation.
[0006] Currently lime plaster is removed mechanically using scalpels, i.e. it is manually dislodged by means of scalpels or small fine-bladed knives.
[0007] Said mechanical method using scalpels for removing the lime plaster requires considerable manual skills to remove the surface layer without damaging the pictorial layer or the layer supporting the pictorial film.
[0008] Said mechanical method using scalpels for removing the lime plaster is very time-consuming as the lime plaster is removed in small portions or small fragments.
[0009] Mechanical removal of the lime plaster by means of scalpels produces small cracks due to the scalpel blade, causes disintegration of micro areas around said cracks and increase in the surface micro porosity with respect to the original pictorial layer which favours the deposit of dirt and micro organisms.
[0010] To remedy all the above-mentioned drawbacks a new manual tool has been developed and produced for the removal of lime plaster from mural and stone supports.
[0011] One object of the new manual tool for the removal of lime plaster is to permit mechanical removal of the lime plaster at a higher speed than with other known mechanical methods.
[0012] A further object of the new manual tool for the removal of lime plaster is to permit removal of the lime plaster without damaging the pictorial layer below.
[0013] A further object of the new manual tool for the removal of lime plaster is not to modify the texture and micro porosity of the surface of the pictorial layer.
[0014] These and further objects, direct and complementary, are achieved by the new manual tool for the removal of lime plaster from mural and stone supports comprising a multi-perforated support on which an active element is fixed formed of a plurality of blades slanting in different directions.
[0015] The tool can comprise, as an active element, an element with a large number of protrusions evenly distributed and with the same depth such as to permit initial roughing of the lime plaster to be removed.
[0016] On the multi-perforated support, on the side opposite said active element, a handle is fixed suitable both for gripping and use of the tool.
[0017] At the corners or in any case in perimetral positions, depth adjusters are applied consisting of sensor pads adjustable in a direction square to the plane of the blades and connected to warning lights and/or buzzers mounted on the support.
[0020] At least two lateral paths corresponding to the positions of the sensor pads are firstly made in the lime plaster until the pictorial surface is exposed. The lime plaster is cleaned by passing the new tool over it with the sensor pads running above said paths. When the sensor pads reach the pictorial surface they activate the indicator lights and/or buzzers to warn the operator who then interrupts the completed cleaning operation.
[0021] The dust and particles removed from the blades of the active element pass through the holes of the multi-perforated support.
[0022] The multi-perforated support of the tool can be produced in different forms, for example a continuous flat support, two convex angular walls or two concave angular walls.
[0023] In the case of a continuous flat support, the active element is applied on one of its largest surfaces, while the handle is applied on the opposite surface.
[0024] In the case of a support formed by two convex walls, the active element is applied on the convex outer sides of the support, while the handle is fixed on the concave side between said two walls. The tool configured in this way is optimal for the removal of lime plaster in corners between the walls of a room or a similar environment.
[0025] In the case of a support formed by two concave walls, the active element is applied on the concave inner sides of the support, while the handle is fixed on the convex outer side between said two walls. The tool configured in this way is optimal for the removal of lime plaster from edges between the walls of two adjacent rooms or environments, for example from the edges of a door, a window or similar.
[0026] The multi-perforated support and active element can have other forms in order to adapt to the specific requirements of the surfaces to be treated.
[0027] The tool constituted as above is passed over the surface of the lime plaster to be removed with the blades of the active element in direct contact with the surface of the lime plaster. Each time the tool runs over the surface of the lime plaster, the blades of the active element remove a surface layer of the lime plaster. Said particles of lime plaster removed are eliminated from the active element and the wall via the holes of the multi-perforated support.
[0028] The characteristics of the new tool will be better clarified by the following description with reference to the drawings, attached by way of non-limiting example.
[0031] In this example the support (1) consists of a metal plate of generically rectangular shape, while the active element (6) consists of a series of parallel blades (6) slanting both with respect to the surface of the support (1) and with respect to the lateral edge of the support (1). On the side of the metal plate constituting the support (1) opposite the active element (6) there is a handle (4) and supports for the sensor pads (5b).
[0032] When said sensor pads (5b) are rotated, the circular foot (5b3) is moved parallel to the active element (2).
[0034] Figures 2a, 2b and 2c show an axonometric view, a lateral section (S-S) and a rear view respectively of a new tool (U), in this example a tool (U) for roughing the surface of the lime plaster.
[0035] The tool (U) comprises a multi-perforated support (1) on one side of which an active element (2) is applied.
[0036] In this example the multi-perforated support (1) consists of a metal plate provided with holes (1f) of generically rectangular shape, while the active element (2) consists of a wire mesh made of stretched sheet metal.
[0037] In particular the metal plate constituting the multi-perforated support (1) has corners (1a) cut obliquely and edges (1b) folded square to the surface of the metal plate (1).
[0038] On the surface of the metal plate of the multi-perforated support (1), opposite said folded edges (1 b), the active element is applied, i.e. the wire mesh made of stretched sheet metal, so that the perimeter portions of said active element (2) envelop the folded edges (1 b) of the metal plate of the multi-perforated support (1).
[0039] Fixing elements (3) provided on said folded edges (1 b) retain and secure the edges of the active element (2) making it integral with the multi-perforated support (1).
[0040] On the side of the metal plate constituting the multi-perforated support (1), opposite the active element (2) there is a handle (4) and supports (5a) for the sensor pads (5b).
[0041] Said supports (5a) are positioned preferably in the corners, and in any case in a perimetral position, of the metal plate constituting the multi-perforated support (1). The sensor pads (5b) consist, in this example, of threaded pins (5b1) which tighten in said supports (5a) provided with a knob (5b2), on the side of the handle (4), and a circular foot (5b3), on the side of the active element (2). When said sensor pads (5b) are rotated, the circular foot (5b3) is moved parallel to the active element (2).
[0042] The light indicators and/or buzzers are included in each support (5a) of the sensor pad (5b).
1. Tool (V, U) for the removal of lime plaster from mural and stone supports characterised in that it comprises a support (1) provided on one side with a handle or grip (4), having
on the opposite side an active element (2, 6) suitable for the removal of a surface
thickness of lime plaster.
2. Manual tool (V) according to claim 1, characterised in that said active element (6) comprises a plurality of parallel blades slanting with respect
to the surface of the support (1) and with respect to the edges of said support (1).
3. Manual tool (U) according to claim 1, characterised in that said active element (2) consists of a wire mesh made of stretched sheet metal.
4. Manual tool (V, U) according to the preceding claims, characterised in that said support (1) has one or more sensor pads (5b) which can move in a direction square
to the median operating plane of said active element (2, 6).
5. Manual tool (V, U) according to the preceding claim, characterised in that said sensor pads (5b) are connected to light indicators and/or buzzers present on
the support (1).
6. Manual tool according to claims 4 and 5, characterised in that said sensor pads (5b) are arranged in a perimetral position on said support (1).
7. Manual tool (V, U) according to the preceding claims, characterised in that said support (1) is provided with a plurality of holes (1f).
8. Manual tool according to the preceding claims, characterised in that said support (1) is a substantially flat element and wherein said active element
(2, 6) is a substantially flat element (2, 6).
9. Manual tool according to claims 1, 2, 3, 4, 5, 6, 7, characterised in that said support (1) is an element formed by two angular walls, and wherein said active
element (2, 6) is applied on the non-facing outer surfaces of said two angular walls,
i.e. on the convex side, and wherein the handle (4) is applied to said support (1)
between the facing inner surfaces of said angular walls.
10. Manual tool according to claims 1, 2, 3, 4, 5, 6, 7, characterised in that said support (1) is an element formed by two angular walls, wherein said active element
(2, 6) is applied on the facing inner surfaces of said two angular walls, i.e. on
the concave side, and wherein the handle (4) is applied on said support (1) between
the non-facing outer surfaces of said angular walls.