The subject of the invention is a painting loom consisting of a wooden frame and angle pieces, and equipped with extension profiles located between its adjacent arms.

The prior art knows painting looms consisting of a rectangular frame and typically reinforced with brackets arranged inside the frame in a crosswise manner. These looms are characterised by poor stability and no resistance to changing weather. The dimensions of these looms cannot be regulated in a wide range.

Patent PL 213736 Bl discloses a painting loom whose arms are made of metal profiles, whose corners include assemblies of components seated in arm profiles that allow, after placing canvas in the loom, moving the arms against each other (with the arms connected via a slantwise mounted bracket). The bracket is supported by locking pieces seated in a sliding manner in the profiles of the arms and the bracket. The structure of the loom, according to the invention, enables stepless regulation of its external dimensions.

French patent No. 2439683 is characterised in that its adjacent arms are connected with a connecting piece and tensioning screws, with springs on their tops. The tensioning screws are supported with locking angle pieces attached to the arms. The painting loom is additionally reinforced with brackets mounted within the fame in a crosswise manner. Screws with springs are mounted inside the brackets. The screws are supported by angle pieces attached to the frame arms.

From the application GB230094A there is known sewing, work-holders for.-A stretching-appliance for artists' canvases, tapestry, &c. comprises four anglepieces, which are secured to the sides e of the stretching-frame by nails or the like. The sides of the frame are forced away from the angle- pieces by means of screw bolts, the nails being partially drawn out.

The application GB1282979A exposes a set of elements for assembling dilater frames for paintings or canvas in which the side members of a frame for stretching a picture canvas are connected together by metal elements each comprising a pair of parallel plates inter-connected by a web which is equal in width to the thickness of the side members and which is accommodated in slots formed in the side members. Two metal elements may be applied to each corner of a frame, which may be strengthened by cross-bars inter-connected by a cross-shaped metal element and joined to the side members by further metal elements each having a pair of plates connected by a web which is inserted into a slot in the cross-bar and being screwed to a side member. The frame may be slightly expanded by wedges disposed between the head of the cross-bar and the adjacent side member or by screw stretchers.

The application GB1437399A exposes an expansible frame for stretching canvas includes strips, which have at each end two cavities for reciving an L-shaped corner elements whose arms are slidable along the cavities. A nut is provided to adjust the position of the arms in the cavities. Recesses are for engagement by a tool (not shown) to effect rotation of the nut. In another embodiment, the adjustment of the strips is by means of wedges mounted on a threaded shank being drawn together by a nut. The strips are held together by corner elements.

In the application GB2415414A there is exposed the nail-free interchangeable canvas frame comprises brackets with fixing parts. Each bracket has a clasp structure. The brackets are connected to each other by corner parts in slots to form a frame body. Canvas is disposed on the front side of the brackets over protruding part which keeps the canvas suspended clear of the frame. Clasp structure is on the rear of bracket or on its side. Fixing part, having the form of a clasp or clip, fastens the periphery of the canvas into a clasp groove. The acute angle and plurality of slightly protruding parts prevent the canvas from loosening. Fixing part also has toothed structures. This allows the tightness between the fixing part and bracket to be adjusted. The canvas is stretched and tensioned by means of variable length adjustment parts.

From the application GB2470956A there is known a joint for an artist's stretcher comprises a first frame member, a second frame member and a tenon, the first and second frame members each having a mortise at an end and being arranged such that, in use, said ends abut to provide a mitre. The tenon engages each mortise to join the first frame member to the second frame member and includes spring means such that, in use, a tension is provided between the first and second frame members

From the application US4319420A there is known a spring tension wire clamp apparatus includes a screw adapted to extend into a wooden frame with a spacer between the frame and a clamp which extends outwardly from the screw and adapted to be disposed against a canvas frame for holding the canvas frame into the picture frame.

From the application US4549596A we know a frame for stretching artists' canvases comprises hollow sections, in the recesses of which are inserted an insert that forms an angle at the corners. Each insert has a notch in which the bent end of a square spring fits. The spring is solid at the other end with a block that can slide in a guide and is provided with a tension screw. By the screw being tightened, the sections are thrust outward, leaving a space between them, and causing the stretching of the canvas. The application US2014326420A1 exposes a stretched artist canvas frame system is supported with a rigid foam back to either allow artists to apply pressure to a canvas without stretching it and causing sagging, or to allow artists to use the stretched artist canvas as an alternative for artists who paint on board. The frame system is a light weight alternative to painting on board, especially when the paintings become very large. The frame system provides the texture of canvas but the stiffness of a board by supporting the board with a lightweight rigid extruded foam. The frame system gives the artist the choice of painting on canvas or the feel of painting on board. The rigid foam back allows the artist to even create a smooth board finish if they choose through priming techniques. As the canvas gets larger, they do not get prohibitively heavier.

The application EP0102922A1 exposes the frame comprises sections of shape, in the recesses of which are inserted an insert that forms an angle at the corners. Each insert exhibits a notch in which the bent end of a square spring fits, the spring is solid at the other end with a block that can slide in a guide of the shape and is provided with a tension screw. By the screw being tightened, the sections of shape are thrust outward, leaving a space between them, and causing the stretching of the canvas.

In the application WO2011103663A1 there is exposed a canvas stretching assembly which has adjustable stretching bars connecting in an end-to- end configuration that allow for the stretching of a canvas, even after the canvas is mounted thereon, with the degree of stretching being adjustable in multiple directions. The canvas stretching assembly, when disassembled, may be compactly stored, which is especially appreciated for shipment purposes.

The nature of the invention is a painting loom consisting of a wooden frame braced with locking angle pieces, and equipped with extension profiles located between its adjacent arms. The extension profiles consist of an external strip and a parallel internal strip. The top and bottom edge of the internal strip, as well as its inner side, include linear racks. The external strip includes the following: a system of gears perfectly overlapping the linear racks, a ratchet system, and a rotating mechanism. The gears of the system are fixed via pins to the external strip. The ratchet system consists of a trigger mounted by a pin, a counterpiece, and a spring inserted onto the handle. The entire ratchet system is attached to the external strip. The extreme ends of both strips are equipped with flat pieces ended with spikes.

Preferably, the extension profiles are made of aluminium.

Preferably, there are two extension profiles.

Preferably, the pins that fasten the gears are made of aluminium. The main advantage of the subject of the invention is the ability to adjust the frame. The solution under the patent application is characterised by high rigidity and stability, which facilitates painting on canvas as well as the display of the finished painting. The invention also enables multiple uses of the extension profiles. The device according to the invention is a universal solution. It has broad applicability as a tensioning component of a painting loom. The invention is a substantial modification over the standard solution since it introduces the possibility of stepless adjustment of the canvas. The invention can be used both in looms with a crosswise bracket and without it.

The subject is shown as an embodiment in schematic figures, in which Fig. 1 shows an axonometric view of the front of the painting loom, Fig. 2 shows an axonometric view of the back of the painting loom, Fig. 3 shows the front of the extension profile, Fig. 4 shows the back of the extension profile, Fig. 5 shows the top view of the back of the extension profile, Fig. 6 shows the cross-section of the extension profile, Fig. 7 is a schematic drawing of the interior of the extension profile, Fig. 8 shows the top view of the outer part of the extension profile, Fig. 9 is a schematic drawing of the angle piece.

The invention in the embodiment according to Fig. 1-14 is made of a wooden frame 1 braced with locking angle pieces 2, and equipped with extension profiles 3 located between its adjacent arms. The extension profiles consist of an external strip 4 and a parallel internal strip 5. The top and bottom edge of the internal strip 5, as well as its inner side, include linear racks 6. The external strip includes the following: a system of gears 7 perfectly overlapping the linear racks 6, a ratchet system 8 and a rotating mechanism 9. The gears of the system 7 are fixed via pins 10 to the external strip 4. The ratchet system 8 consists of a trigger 11 mounted by a pin 10, a counterpiece 12 and a spring 13 inserted onto the handle 14. The entire ratchet system 8 is attached to the external strip 4. When the gears 6 are set in motion, the external strip 4 and internal strip 5 move apart in an even manner, which extends the loom arms and tensions the canvas. The extreme ends of both strips are equipped with flat pieces 15 ended with spikes 16 to anchor the device in the frame of the loom. The arms in the tensioned position are locked by locking angle pieces 2 equipped with spikes that can be manually attached to the frame. Thus prepared canvas is ready to be displayed. The profiles 3 that extend the arms can be left in place to function as a tensioning device or removed to be reused with the next painting loom. The device is released by unlocking the ratchet on the gear.