EP2665608A1

EP2665608A1 - Canvas-covered framework

Info

Publication number: EP2665608A1
Application number: EP12703723.2A
Authority: EP
Inventors: Riccardo Elio PIERACCINI
Original assignee: Per Belle Arti Di Pieraccini Riccardo Elio
Current assignee: Per Belle Arti Di Pieraccini Riccardo Elio
Priority date: 2011-01-21
Filing date: 2012-01-20
Publication date: 2013-11-27
Also published as: WO2012098231A9; IT1403568B1; ITFI20110013A1; WO2012098231A1

Abstract

The present invention concerns the field of supports for canvases and in particular a framework that can be made by an end user alone (directly, like a painter, artist or other, or indirectly, like for example a craftsman or a retailer in general).

Description

CANVAS-COVERED FRAMEWORK

DESCRIPTION

Field of the invention

Background of the invention

Currently, frameworks for supporting and pulling canvases are made from wooden splints cut to size and then fitted together to form a rigid structure on which to fix the canvas. In the present application, by the term canvas it is meant any flexible or semi-flexible surface made from cloth or another material, suitable for being supported on a wooden framework; in particular, for the purposes of the present application, are consider "canvases", artists' canvases for supporting paintings (commonly made from jute, cotton, flax, etc.), tapestries, sheets of printed fabric, sheets of plastic material intended to be decorated or sheets of moulded plastic material (used, for example and not for limiting purposes, for commercial or promotional purposes), etc.

In case of quadrilateral frameworks with 90° angles (rectangular or square) the fitting together can be carried out by cutting the splints to form a mitre joint, i.e. cutting the free ends of the splint intended for the connection according to cutting planes inclined by 45°. In order to stabilize the framework there can also be one or more inner cross-members (which connect opposite or adjacent splints of the framework itself).

In order to obtain this type of frameworks, the method for fitting together the splints is essential; amongst the various possible manufacturing techniques, in one currently used the fitting together is carried out so that the splints mutually join according to an angle of 45° on the side where the canvas rests; on the back, on the other hand, back portions of the two splints have squared faces allowing correct alignment during the assembly step.

Once the framework is assembled, the canvas is pulled and fixed, (usually through nailing, stapling or another analogous method); however, once fastened, the canvas must be perfectly pulled tight or in any case pulled with the degree of tension required by the end user (like, for example, the painter). Frameworks of standard sizes are commonly made in series and therefore can easily be found on the market with a canvas pulled and ready for use; however, there is a common and strong need for frameworks of non-standard sizes and shapes (like, for example and not for limiting purposes, hexagonal, octagonal, circular, etc.), which must therefore be custom made as required by the artist.

Consequently, this type of framework, as well as having a greater cost than standard frameworks, takes longer to produce and therefore involves significant waiting times for the customer.

Frameworks produced in series have types of coupling that can only be made with special machinery and/or in successive processing steps; similarly, non-standard or oversized frameworks are made by adapting the production lines of standard or series frameworks or with hand-made techniques; therefore, their construction is carried out by skilled workers and special machinery, which makes them complex to produce.

Considering the above, it is quite common for the artists, craftsman or handicraft laboratory, to realize directly on their own the non-standard frameworks according to the need.

In this case, in order to pull the canvas tight, wedges are employed, preferably made from a wood with lower hardness than that used for the splints and the cross members constituting the framework, which are inserted in the fitting between two consecutive splints, so as to move them apart from one another. To this purpose, the wedges are cut so as to have a pronouncedly acute angle of penetration. Such an angle promotes the penetration of the wedge inside the mobile coupling between two consecutive splints, so as to achieve, as a function of the penetration of the wedge itself, the pulling more or less tight of the canvas to the extent desired by the painter. This system is however inaccurate, results in a poor appearance of the resulting framework and required skilled craftsmanship for cutting the splints and adjusting the wedges.

Documents US41144660 and US2009/0057364 disclose adjustment systems for pulling the canvas according to the preamble of enclosed claim 1. However, according to such systems it is necessary to provide a structurally complex device, not easy end effective to be assembled and operated, and requiring troublesome and weakening working on the framework splints. These systems, even when might be suitable for industrial production, are therefore completely inappropriate for self-made or handcraft production. Moreover, in the adjustment process the material of the splints, normally wood, becomes directly stressed, this resulting in the framework becoming damaged or worn.

Summary of the invention

The object of the present invention is therefore to make it possible even for people without specific ability or professional skills to make frameworks intended for the application of canvases, in particular frameworks of non-standard sizes, using machinery and tools commonly found on the market.

Another object of the invention is to provide a system for obtaining such frameworks, and in particular for pulling the canvas ready for use, making use of a structurally simple device, easy end effective to be installed and operated, that does not require difficult working on the splints.

Yet another object of the invention is to provide a system and a framework of the above mentioned type, in which the structure of the framework is not weakened after construction, and the framework obtained is smooth, aesthetically pleasant, with no damages resulting from the adjustment required for pulling the canvas.

A further purpose of the present invention is to provide a framework that can be easily and quickly assembled, with low manufacturing costs.

These and other purposes are accomplished by the framework and insert according to the invention the essential characteristics of which are defined, respectively, in attached claims 1 and 13.

Brief description of the drawings

The characteristics and advantages of the framework and insert according to the invention will become clearer from the following description of embodiments thereof, given as a non-limiting example, with reference to the attached drawings, in which:

- figure 1 is the framework according to the invention, in which it is possible to see inserts for the connection of splints constituting the framework itself;

- figure 2 is a perspective view of a substantially heart-shaped insert for the connection at 90° of two consecutive splints;

- figure 3 shows, again in a perspective and exploded view, the insert and in particular pushers for adjusting the tension of a canvas fastened to the framework;

- figure 4 is a detailed view of the connection at 90° between two consecutive splints, through the substantially heart-shaped insert of the previous figures;

- figure 5 is a perspective view of a straightly elongated insert for the connection of a cross splint to a boundary splint;

- figure 6 shows a perspective and exploded view of the insert of figure 5 in which it is also possible to see a pusher for adjusting the tension of the canvas;

- figure 7 is a perspective view of a first embodiment of the heart-shaped insert represented in the previous figures, having a single driving screw;

- figure 8 shows a second embodiment of the heart-shaped insert of the previous figures in which driving screws are embedded in the insert and arranged longitudinally; and

- figure 9 is lastly an embodiment for frameworks of great thickness in which, for the connection of two consecutive splints, supplementary stiffening plates are used.

Detailed description of the invention

With reference to figures from 1 to 4, a framework according to the invention comprises a plurality of splints 1 , coupled together, like in the illustrated example, in pairs at right angle to form a boundary frame 10. In particular, in the example illustrated in the figures, the boundary frame 10 has a rectangular shape and the splints 1 are therefore four in number.

According to the invention two adjacent splints 1 are connected together by means of an insert, such as a substantially a heart-shaped insert 2; in particular, in the embodiment illustrated in the figures, each heart-shaped insert 2 comprises two arms 20a arranged so as to form a right angle corresponding to the connection angle of the two splints that the insert itself is intended to join; for this purpose, as shown in the figures and as will be described better hereafter, each arm 20a is intended to couple with a free end 1a of the splint 1.

To be more specific, each heart-shaped insert 2 comprises a flat base 21 from which a ridge 22 extends in a central position. The ridge 22 extends from the flat base with a greater thickness than that of the base itself, so as to allow the insertion of driving means such as elements like, for example, but not for limiting purposes, screws 23 arranged so that the axis X of extension of the screws themselves, and also the direction of advancement thereof, is orthogonal to the plane defined by the boundary frame 10 that also represents the plane on which the canvas lies (once it is fixed to the framework).

The screws 23 act on pushing means such as pushers 24 (figure 4) at least partially penetrating the ridge 22. In particular, the pushers 24 have at least one slanting surface 24a (figure 3), housed in a cavity of the ridge 22, matching in frictional contact engagement with a conical driving surface 23a defined by a head of a screw 23. Each screw is screwed in a threaded hole (not visible) affecting the ridge 22. Consequently, there are the same number of pushers 24 as there are screws 23.

Each pusher 24 runs, under the driving action of the respective screw 23 (the transmission being carried out via the frictional arrangement between the above mentioned surfaces) on suitable guiding means such as a grooves 25 formed in a top face of the flat base 21 (i. e. the face from which the ridge 22 extends). The pusher 24 comprises a pusher member 24d adapted to partially penetrate the cavity of the ridge 22 and defining at a front end a pushing front end surface 24c for pushing on the splint (as will be made clearer hereafter), and at a rear end the said surface 24a matching with the screw. Such matching surface 24a, e.g. a conical one for better coupling with the head of the screw, has a cutout 24e for permitting the passage of the stem of the screw 23. A flat projection 24b can also project frontally from the front end surface 24c, so as to engage flush within a front portion of the groove 25 not occupied by the pusher member 24d, so as to make the sliding engagement more precise and stable.

From a first position corresponding to a maximum rearward displaced position of the pusher member 24d towards the ridge 22 to a second or pushing position, the pusher moves according to a pushing direction A (parallel with the plane of the framework).

As shown in figure 1 , and with reference also to figures 5 and 6, in order to reinforce the structure of the framework, there can also be one or more crossbeam splints 3; in the described example there is a crossbeam 3 that transversally connects two opposite splints 1 . In this case, the crossbeam 3 is connected to each splint through a substantially straightly elongated insert 4. The same insert 4 can also be used for the connection of cross-pieces (one or more than one) or crossbeams arranged diagonally that join, usually near to the crossover point, two adjacent splints.

Such a straightly elongated insert 4 has an embodiment per se analogous to the substantially heart-shaped insert 2; parts equal or analogous to the ones already described for the previous embodiment are denoted at corresponding numerals (e.g. the pusher member 44d with the pushing surface 44c and the rear driving surface 44a correspond to parts 24d, 24c, 24a, respectively, of the previous embodiment) . However, while in the previous example a screw driven pusher 24 was provided for each arm 20a of the body 20, in this case only one pusher 44 is provided, and at the opposite end of the ridge 42 a fixed pushing surface 42a for engagement with a seat 5 is defined.

The framework according to the invention is then obtained as follows: using a standard milling cutting tool, partially blind seats 5 are formed in the splints 1 , each splint having a main surface 1a, 3a parallel and opposite the side to be later used fore resting the canvas, and side surfaces 1 b, 3b substantially orthogonal with the main surface 1a, 3a. The seats 5, formed either on an end side surface or on a lateral side surface (depending on the type of junction as visible comparing the example of figures 2 to 4 with that of figures 5 and 6), comprises a slit 50 of comparable dimensions to those of the flat base 21 , 41 so as to engage therewith and a notch 51 opening on the main surface 1a, 3a and defining a coupling surface 51a, having a complementary shape with respect to the pushing end front surface 24c, 44c.

As can be seen in figure 4, to make a rectangular-shaped framework, the splints 1 are initially prepared by cutting the free ends to form a right angle (i.e. according to a cutting plane inclined by 45°) and on a end side face 1b (figure 3) the seat 5 is made; In the two seats 5 the arms 20a of the body 20 are inserted, until the two splints intended for connection come into contact along the respective faces 1 b.

Once the framework has been thus formed, and the canvas (not shown) is fixed (for example by nailing), the user can adjust its tension by turning the screws 23, e.g. via a normal screwing tool. In particular, a direct movement according to a movement direction corresponding to the penetration direction of each screw 23, orthogonal with the canvas and the plane of the framework, urges a movement in the direction A, through the frictional contact between the conical surfaces 23a of the screws and the slanting surfaces 24a of the pushing means 24. As a consequence, the pushers 24, with the front pushing surfaces 24c, will exert a force on the coupling surfaces 51a of the seats 5, pushing the splints so as to move them apart from one another; such forcing on the connection of the splints 1 results in the canvas being pulled tight.

The described adjustment system allows for a better and more precise squaring, and indeed it is possible to act on each single splint: by varying the penetration of the screw in the insert the sliding of the relative pusher is adjusted and, consequently, the spacing of the splint associated with said pusher is also adjusted, whereas the adjacent splint connected through the insert is not involved in the adjustment. The friction contact force driving the pushing movement is exchanged through different parts of the insert, normally metal for the screw and a synthetic material for the body, so that the wood of the splints does not suffer any stress or damage (the pushing contact exchanged through pusher and splint is not frictional and is uniformly distributed along the relevant contact surfaces, so that no significant stresses may occur).

Similarly, it is possible to act on the screw 43 of a straight elongated insert 4, to achieve the same forcing action by the crossbeam splint 3 on a boundary splint 1 to which it is connected as visible in figures 1 , 5 and 6.

According to a first variant embodiment shown in figure 7 the insert 2' can also comprise a single screw 23' for driving both pushing means 24'. In a second variant embodiment of the heart-shaped insert 2" (figure 8), on the other hand, two revolving driving elements 23" are embedded in the ridge 22" and arranged longitudinally (i.e. with axis X" parallel with the plane defined by said boundary frame 10 on which, once fixed to the framework, the canvas lies); the revolving elements 23" can drive the pushers 24" through a pinion rack engagement or a worm drive.

For heavier models of frameworks or in any cases ones formed from splints of greater thickness, there are also solutions with supplementary plates 7, possibly of a stronger material than that of the body 20, 40, arranged parallel on juxtaposed planes (figure 9). In this case, on each free end 1a of each splint 1 it is necessary to form a corresponding number of supplementary slits each for engaging with a supplementary plates 7 necessary for the connection. Again in figure 9 it is possible to see a tool, such as a tip of a screwdriver 6, for moving the screw 23.

The components for making the framework can also be commercialised in a kit; in particular, the kit will comprise the materials to be cut to size to obtain the splints of the desired length and optional ly the cross-pieces or crossbeam splints, the substantially heart-shaped 2 or straight elongated 4 inserts as described and a milling cutting tool designed for making the seats 5.

The insert can also have different shapes, for example, in the case of heart- shaped inserts, the arms can be arranged with angles different from 90°, so as to make frameworks of different shapes, such as triangular, hexagonal, octagonal ones, etc.

The advantages of the system according to the invention are therefore, non- exhaustively, the following.

- ease of construction of the framework, that can be manufactured in a few minutes even by unskilled users;

- the possibility of making the framework using machinery that can easily be found on the market, of low power and bulk and of low cost;

- the adjustment of the tension of the canvas takes place without the use of pushers, hammers or other tools that would require specific professional capability;

- the framework has aesthetic value, i.e. the sides are smooth, without holes and the corners are whole, not having any coupling mark on the outside;

- the process is suitable for various types of profile and splints of different thicknesses;

- the process is extremely versatile, i.e. it can be used to make non-standard frameworks of small, medium-large dimensions, or, using inserts made from specific materials (like plastic, metal, alloy or other), to make frameworks of large dimensions (like those used in restoration works);

- the system is extremely precise and promotes the better and more precise sq uaring of the framework because the adjustment is carried out by driving independently on the single splint.

- the insert is a structurally simple and compact device, easy to be operated; - no troublesome or weakening working on the framework splints are carried out; the splint remain substantially integral and with no critical corners or fragile walls/projections;

- the material of the splints, normally wood, does not become directly stressed, and the framework does not suffer damages, remaining also aesthetically pleasant (a contribution in this respect is also given by the same insert with its compactness and its almost total insertion and integration with the frame, the driving elements acting directly over the base and not being distributed along the same splint nor acting thereon).

The present invention has been described up to now with reference to its preferred embodiments. It should be understood that there can be other embodiments that come from the same inventive core, all covered by the scope of protection of the claims given below.

Claims

1. A framework for the attachment and the support of a canvas, comprising a plurality of splints (1 , 3) connected to define at least a boundary frame (10) of said framework arranged on a plane, the framework further comprising a plurality of inserts, each arranged at a junction between two of said splints (1 , 3), each insert (2) comprising: a body (20, 40) engaging within a corresponding seat (5) formed in a respective splint (1 , 3); pushing means (24, 44); and driving means (23, 43) of said pushing means (24, 44), said pushing means (24, 44) being movable over said plane in response to the operation of said driving means (23, 43), to push mutually away said splints to obtain the adjustable pulling of said canvas, characterized in that said body (20, 40) comprises guide means (25, 45) for guiding the sliding of said pushing means (24, 44), said pushing means (24, 44) comprising a pushing front end surface (24c, 44c) for contacting a coupling surface (51a) of said seat (5), said driving means (23,

43) being arranged over said body (20, 40) in a transmission engagement with said pushing means (24, 44).

2. The framework according to claim 1 , wherein said driving means (23, 43) are arranged along a driving direction (X, X') orthogonal with said plane, and comprise a driving surface (23a, 43a) in frictional contact relationship with said pushing means (24,

44) .

3. The framework according to claim 2, wherein said driving means (23, 43) comprise at least one screw (23, 43) engaged with a corresponding threaded hole formed in said body (20, 40), said driving surface (23a, 43a) being a conical surface of a head of said screw (23, 43), said pushing means (24, 44) comprising correspondingly a matching slanting surface (24a , 44a) for frictional engagement with said conical surface (23a, 43a) formed at a rear end opposite said pushing front end surface (24c, 44c).

4. The framework according to claim 3, wherein said matching slanting surface (24a, 44a) at the rear end of said pushing means (24, 44) is a conical surface.

5. The framework according to claim 4, wherein said rear end of said pushing means (24, 44) comprises a cutout (24e, 44e) formed in said conical surface (24a, 44a) for permitting the passage of said screw (23, 43).

6. The framework according to any of the previous claims, wherein said pushing front end surface comprises a curved surface (24c, 44c) having a curvature axis orthogonal with said plane.

7. The framework according to any of the previous claims, wherein said body comprises a substantially flat base (21 , 41) parallel with said plane, and a ridge (22, 42) projecting from said flat base (21 , 41) and crossed with threaded engagement by said driving means (23, 43), said guide means (25, 45) comprising a groove (25, 45) formed in said base, said pushing means (24, 44) comprising a flat projection (24b, 44b) slidingly flush within said groove, said pushing surface (24a, 44a) rising from said flat projection (24b, 44b) and being defined by a pusher member (24d, 44d) slidably housed within a cavity of said ridge (22, 42) and engaging with said driving means (23, 43).

8. The framework according to claim 7, wherein each splint (1 , 3) comprises a main surface (1a, 3a) parallel and opposite said canvas, and side surfaces (1 b, 3b) substantially orthogonal with said main surface (1a, 3a), said seat (5) comprises a slit (50) engaging with said flat base (21 , 41) and formed in one of said side surfaces of a respective splint, and a notch (51) opening on said main surface (1 a, 3a) and defining said coupling surface (51a).

9. The framework according to any of the previous claims, wherein said body (2) comprises two arms (20a, 40a) mutually at right angles, each supporting corresponding pushing means (24, 44).

10. The framework according to claim 9, wherein independent driving means (23, 43) are provided for respective pushing means (24, 44).

11. The framework according to claim 9, wherein single driving means (23, 43) are provided for driving both pushing means (24, 44).

12. The framework according to any of the claims from 1 to 8, wherein said frame further comprises a body (40) having an elongated straight shape defining a first end supporting said pushing means (44) with corresponding driving means (43), and a fixed second end comprising a fixed pushing surface (42a) for contacting a matching surface (51a) of said seat (5).

13. An insert for mutually connecting two splints (1 , 3) of a canvas framework, comprising a body (20, 40) for engagement with respective seats (5) formed in said splints, splint pushing means (24, 44), and driving means (23, 43) of said pushing means (24, 44), said pushing means (24, 44) being movable in response to the operation of said driving means (23, 43), to push mutually away said splints to obtain the adjustable pulling of said canvas, characterized in that said body (20, 40) comprises guide means (25, 45) for guiding the sliding of said pushing means (24, 44), said pushing means (24, 44) comprising a pushing front end surface (24c, 44c) for contacting a coupling surface (51a) of said seat (5), said driving means (23, 43) being arranged over said body (20, 40) in a transmission engagement with said pushing means (24, 44).

14. The insert according to claim 13, wherein said body (20, 40) comprises a substantially flat base (21 , 41) adapted to be arranged parallel with said canvas, said driving means (23, 43) being arranged along a driving direction (X, X') orthogonal with said base, and comprising a driving surface (23a, 43a) in frictional contact relationship with said pushing means (24, 44).

15. The insert according to claim 14, wherein said driving means (23, 43) comprise at least one screw (23, 43) engaged with a corresponding threaded hole formed in said body (20, 40), said driving surface (23a, 43a) being a conical surface of a head of said screw (23, 43), said pushing means (24, 44) comprising correspondingly a matching slanting surface (24a, 44a) for frictional engagement with said conical surface (23a, 43a) formed at a rear end opposite said pushing front end surface (24c, 44c).

16. The insert according to claim 15, wherein said matching slanting surface (24a, 44a) at the rear end of said pushing means (24, 44) is a conical surface.

17. The insert according to claim 16, wherein said rear end of said pushing means (24, 44) comprises a cutout (24e, 44e) formed in said conical surface (24a, 44a) for permitting the passage of said screw (23, 43).

18. The insert according to any of the claims from 13 to 17, wherein said pushing front end surface comprises a curved surface (24c, 44c) having a curvature axis orthogonal with said base (21 , 41).

19. The insert according to any of the claims from 13 to 18, wherein said body comprises a ridge (22, 42) projecting from said flat base (21 , 41) and crossed by said driving means (23, 43), said guide means (25, 45) comprising a groove (25, 45) formed in said base, said pushing means (24, 44) comprising a flat projection (24b, 44b) slidingly flush within said groove, said pushing surface (24a, 44a) rising from said flat projection (24b, 44b) and being defined by a pusher member (24d, 44d) slidably housed within said ridge (22, 42) and engaging with said driving means (23, 43).

20. The insert according to any of the claims from 13 to 19, wherein said body (20) comprises two arms (20a, 40a) mutually at right angles, each supporting corresponding pushing means (24, 44).

21. The insert according to claim 20, wherein independent driving means (23, 43) are provided for respective pushing means (24, 44).

22. The insert according to claim 20, wherein single driving means (23, 43) are provided for driving both pushing means (24, 44).

23. The insert according to any of the claims from 13 to 19, wherein said frame further comprises a body (40) having an elongated straight shape defining a first end supporting said pushing means (44) with corresponding driving means (43), and a fixed second end comprising a fixed pushing surface (42a) for contacting a coupling surface (51a) of said seat (5).

24. A kit comprising a plurality of splints, a plurality of inserts according to any of the claims from 13 to 23, and milling cutting means adapted to form insert engagement seats in said splints.