Patent Application
20060101759
The present invention relates to devices that can be used to tension and secure a canvas or a sheet of paper. Such devices may, for example, be used to post public poster advertising or as art or decorative frames.
The invention relates more especially to a frame or stretcher structure combined with an arrangement of components in recesses making it possible to reversibly attach a canvas to a stretcher by wedging.
Generally speaking, the use of elongated deformable battens to reversibly attach a canvas to a stretcher by wedging is known.
Document FR 2 639 879 describes a stretcher for a canvas having a groove around its periphery. The tensioning device consists of an elongated batten comprising a flat base emerging from the groove and two parallel wings which protrude from said flat base and have enlargements on their opposite surfaces intended to click into a restricted mouth of the groove made in the stretcher.
The tensioning device has portions that are substantially perpendicular which are subjected to shear stresses in the area where they are joined when the two protruding wings are inserted into the mouth of the groove. Although this deformation is necessary in order to wedge the canvas into the groove of the stretcher, it nevertheless makes the batten fragile and even destroys it after a certain number of uses.
In addition, with such a device, wedging of the canvas is obtained on the ends of the walls that form the restricted mouth of the groove by means of two sharp opposite-facing edges. This arrangement then creates friction on the sharp edges which will consequently damage the canvas each time the batten is fitted into or removed from the groove.
Document BE 848 203 also describes a device making it possible to tension and secure a canvas on a frame. In this case a batten penetrates into a U-shaped groove. The batten may, in particular, have a V-shaped cross section and wedge the canvas by means of the two long edges of the wings of the V. The canvas is therefore wedged between a flat surface of the groove and a sharp edge of the batten.
Consequently, as before, this type of arrangement quickly damages the canvas and does not make it possible to repeatedly mount and dismount the canvas from the frame without damaging it.
The present invention therefore relates to a device capable of tensioning and securing a canvas comprising a stretcher having a groove and at least one deformable batten. The canvas is tensioned and secured on the stretcher by wedging it between the groove and the deformable batten.
This deformable batten has a substantially V-shaped section which is oriented towards the bottom of the groove. The deformable batten comprises a sharp edge which is used as a pivot to enable the deformation thereof and two flanks which are used to wedge the canvas in the groove.
In other words, the two flanks of the batten which allow wedging pivot relative to the sharp edge of the V which is oriented towards the bottom of the groove.
According to the invention, the device is characterised in that the batten is locked in a narrow section of the groove by means of two enlargements each extending on one flank of the batten in the same direction as the batten.
In other words, the batten is a profile that has two flanks which each have an enlargement on their outer surface.
The batten has a clearance between the enlargements on its flanks which is wider than the narrow section of the stretcher's groove. Pressure exerted on the inside of the batten and the sharp edge of the V makes it possible to move the flanks of the V together thereby allowing the batten to be pushed down into the groove of the stretcher. The enlargements then penetrate into the narrow section and produce self-locking assembly of the canvas.
Thus, wedging of the canvas is obtained between two tangential surfaces inside the groove and near the narrow section. Consequently, the canvas can be mounted and dismounted from the frame without being damaged.
In practice, the batten may also comprise two flaps which extend the flanks and emerge from the groove to make it possible to grip and extract the batten which is locked in the groove.
Depending on the application, the batten which ensures wedging may extend over the entire side or be formed by a plurality of separate lengths.
In other words, in this latter case, in a given direction and on the same side of the stretcher, the canvas can be wedged into a groove by means of several separate components forming lengths of separate battens.
In certain situations, the stretcher can be disassembled into a plurality of segments. This makes it easier to transport and handle.
Advantageously, the stretcher may comprise a plurality of features making it possible to separately mount bracing in order to join, two by two, segments located, in particular, on the opposite sides of the stretcher. These features may be in the form of grooves capable of accommodating means of reversible attachment.
In one particular embodiment, the stretcher may comprise means of hook fastening in order to mount it on a wall. In other words, the stretcher may have a special geometry intended to facilitate hanging it on a wall or, more generally, any type of partition wall.
In practice, fitting the battens can be made easier by means of a tool comprising a rounded edge making it possible to exert pressure on the inside surface of the battens.
A kit comprising a stretcher and battens as well as a tool can be supplied with the canvas and sold as such, i.e. not assembled, in order to reduce the cost of labour, storage and handling.
The user then assembles the frame and positions the canvas relative to it. Cutting the canvas to size very accurately combined with positioning relative to a registration mark on the stretcher makes it possible to apply a predetermined tension to the canvas every time it is mounted. This is made possible by using a canvas made of a non stretchable material.
Consequently, tensioning the canvas does not require any adjustment on the part of the user and is determined by the actual design of the canvas depending on the material used and its dimensions.
The way in which the invention is embodied and its resulting advantages will become more apparent from the description of the following embodiment, given merely by way of example, reference being made to the accompanying drawings in which:
As already stated, the invention relates to a device capable of tensioning and securing a canvas comprising a stretcher having a groove and at least one deformable batten.
As shown in
In the form illustrated, the battens (4) are inserted onto the rear surface of the stretcher (2) but they can also be inserted on any other surface of the stretcher.
Bracing (12) is used to make the structure of the stretcher (2) more rigid. This bracing (12) can be attached to the various lengths that form the stretcher (2) by means of a plurality of features (11) which are shown here in the form of grooves into which a square nut can be inserted. A screw is then used to reversibly attach the bracing (12) to the stretcher (2).
As is apparent in
Wedging of the canvas (1) in the groove (3) is obtained by means of the two flanks (7, 17) of the batten (4) or (14, 24).
A hook-fastening portion (13) may emerge from the profile in a localised or continuous fashion over the entire length of the profile in order to make it easier to attach the stretcher on a wall using the hook.
As shown in
Deformation of the two flanks (7, 17) occurs when the batten(4) is inserted into the groove (3) by pivoting around a sharp edge of the batten (4).
Flaps (8) that extend the two flanks (7, 17) of batten (4) outside the groove make it possible to extract the batten (4) when it is locked in the groove (3).
The groove making it possible to attach the bracing (12) has a narrowed opening which allows a screw (18) to pass through but prevents a square nut (19) from escaping the groove. The various lengths of the stretcher (2) are made in this way as a profile which can have one or more grooves.
From the above description, it is apparent that a device in accordance with the invention has many advantages, in particular:
the geometry of the batten makes it possible to provide a large degree of elasticity capable of withstanding a large number of successive deformation cycles;
the method of manufacturing the deformable batten is simple to use and relatively inexpensive, e.g. an extrusion process, in particular;
finally, the density per metre length of such a profile is very low and this makes it an inexpensive component.
| Number | Date | Country | Kind |
|---|---|---|---|
| 03.08381 | Jul 2003 | FR | national |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/FR04/50293 | Jun 2004 | US |
| Child | 11321909 | Dec 2005 | US |
