(19)
(11) EP 0 945 155 B1

(12) EUROPEAN PATENT SPECIFICATION

(45) Mention of the grant of the patent:
13.10.2004 Bulletin 2004/42

(21) Application number: 99105899.1

(22) Date of filing: 24.03.1999
(51) International Patent Classification (IPC)7A63F 9/08

(54)

Educational game device with sliding tiles to arrange in predetermined sequences

Lernspielvorrichtung mit verschiebbaren Ziegeln, die in bestimmten Folgen anzuordnen sind

Jeu éducatif à carrés coulissants à arranger en séquences prédéterminées


(84) Designated Contracting States:
BE CH DE ES FR GB IT LI NL PT

(30) Priority: 27.03.1998 IT CN980003

(43) Date of publication of application:
29.09.1999 Bulletin 1999/39

(73) Proprietor: Lerda, Bruno
12020 Cuneo (IT)

(72) Inventor:
  • Lerda, Bruno
    12020 Cuneo (IT)

(74) Representative: Apra', Mario 
Apra' Brevetti Via Bertola 2
10121 Torino
10121 Torino (IT)


(56) References cited: : 
DE-C- 847 276
US-A- 4 480 839
US-A- 4 097 049
   
       
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description


    [0001] The present invention relates to an educational game device with sliding tiles to arrange in predetermined sequences.

    [0002] Game devices of the type specified are known in the prior art, for instance from US-A-4097049 which shows a game device with all the features set out in the preamble of claim 1.

    [0003] However, known game devices have the drawback of requiring a fairly anodyne intellectual effort which is therefore often unsatisfying. Furthermore, being of simplified structure, they do not permit of graduation of the level of difficulty.

    [0004] Furthermore, such known game devices are not suitable for visually handicapped or illiterate players.

    [0005] The object of the present invention is to provide an educational game device with sliding tiles to arrange in predetermined sequences, that is designed to stimulate and develop, in the form of an "intelligent game" the user's perceptive insight, logic and sense of geometry, by exchanging the positions of sliding tiles.

    [0006] Another object is to provide a game device as specified, that will allow the level of difficulty of the game to be graduated to suit the ability of the player.

    [0007] A further object is to provide a game device as indicated, that is also suitable for visually disabled or illiterate players.

    [0008] With a view to these objects, the present invention provides an educational game device with sliding tiles to arrange in predetermined sequences, whose essential features form the subject of the characterizing part of Claim 1.

    [0009] Other advantageous features appear in the dependent claims.

    [0010] The aforesaid claims are to be understood as reproduced here in their entirety.

    [0011] The invention is described in detail below with reference to the accompanying drawings, which are provided purely by way of example, in which:
    • Fig. 1 is a plan view of the game device according to the invention in the initial condition of the game;
    • Fig. 2 is a view similar to that of Fig. 1 but illustrating the final condition of the game;
    • Fig. 3 is a plan view of a support or board for the game device according to Figures 1, 2;
    • Fig. 4 is a sectional view on the plane marked IV-IV in Fig. 3;
    • Fig. 5 is a view similar to that of Fig. 1, but in which the game device is provided with moveable peg means which increase the difficulty of the game;
    • Fig. 6 is a side view in the direction of the arrow marked VI in Fig. 5;
    • Figures 7 and 8 are partial views in section through the game device according to Fig. 5, illustrating two different positions of play of a moveable peg;
    • Fig. 9 is a view in partial cross section through the device of Fig. 5, illustrating two sliding game tiles and their respective slideways in the support or board; and
    • Fig. 10 is a view in partial cross section through the device of Fig. 5, illustrating a sliding game block and a slideway for it in the support or board.


    [0012] In the drawings, 10 (Figs. 1, 2) denotes the whole of the educational game device according to the present invention.

    [0013] The said device 10 comprises a quadrilateral support or board 11 (Figs. 3, 4) made of e.g. plastic, on one of whose faces are two mutually adjacent and communicating recessed tracks with rectangular perimeters, namely a principal track 12 and an auxiliary track 13.

    [0014] The track 12, of greater area, comprises a network of longitudinal 12.1 and transverse 12.2 straight perpendicular intersecting slideways (slots) (Fig. 3). In the example illustrated, the track 12 comprises four longitudinal ways 12.1 and six transverse ways 12.2.

    [0015] The auxiliary track 13 of smaller area, on the other hand, comprises a single straight slideway 13.1 that is parallel to the said longitudinal ways 12.1 and lies between two transverse ways 12.2, with which this way 13.1 communicates at its ends. In the example illustrated, the way 13.1 communicates with the second and penultimate of the six transverse ways 12.2.

    [0016] Guided in the said network of ways 12.1, 12.2 are twenty-four quadrilateral sliding game tiles 14, made of e.g. plastic, which occupy the entire area of the track 12, being arranged when at rest in four rows and in six columns. In this arrangement, each tile 14 is at its own intersection between a longitudinal way 12.1 and a transverse way 12.2.

    [0017] In particular, each tile 14 includes a foot with a frustoconical end 14.1 (Fig. 9) engaged with play in a corresponding slideway, 12.1, 12.2, and a flat head 14.2 (of square base in accordance with the example illustrated) which is juxtaposed with play against the head 14.2 of another tile or against an edge of the track 12.

    [0018] An opening 13.2 (Fig. 3) in the way 13.1 allows insertion of the foot 14.1 of each tile, which is then slid, beyond the way 13.1, around the network of ways 12.1, 12.2.

    [0019] A block 15 (Figs. 1, 2) is then inserted, once again through the opening 13.2, into the slideway 13.1 via its foot part 15.1 with the frustoconical end (Fig. 10). The said block 15, which may be made e.g. of plastic, comprises a flat head 15.2 (of rectangular base in accordance with the example illustrated), that occupies part of the track 13, but leaves in this track an unoccupied space 15.3 of variable position and corresponding approximately to the dimensions of the head 14.2 of one tile 14.

    [0020] By means of this arrangement, the block 15 is able to slide along the track 13 in the longitudinal direction only, between two extreme positions, one against the right-hand end of the track, in which the unoccupied space 15.3 is on its left (Fig. 2) and the other against the left-hand end of the same track, in which the unoccupied space 15.3 is on its right (Fig. 1). In each of the said two positions to which the block 15 can be slid, one tile 14 of the row of tiles adjacent to the track 13 (specifically the tile belonging to the second column or to the fifth column) is next to the unoccupied space 15.3, which this tile can occupy by sliding in a direction perpendicular to that of the block 15. This opens up an unoccupied space between the tiles 14 which, by making moves in perpendicular directions, can be rearranged relative to each other within the track 12.

    [0021] As illustrated in Fig. 1, the basic face visible from the outside of the head 14.2 of each tile 14 is coloured, so that at the beginning of the game the said tiles form, for example, in the corners of the track 12, a geometrical arrangement of four identical right-angled triangles having mirror symmetry and having the same colour, and in the centre of the track a rhombus whose sides coincide with the hypotenuses of the four right-angled triangles.

    [0022] The object of the game is, according to the example illustrated, by moving the tiles 14 and the block 15, to exchange the colour of the rhombus with that of the right-angled triangles inscribed within said track 12, so as to obtain the game configuration illustrated in Fig. 2.

    [0023] It will be observed that the dissimilar chromatic configuration of the visible face of the heads 14.2 of the tiles 14 enables the device to be used by illiterate persons also.

    [0024] In addition, in order to render the device 10 useable by the visually disabled also, the visible basic face of the head 14.2 of each tile 14 may include knurling, depressions or reliefs, either instead of or in addition to the chromatic configuration.

    [0025] In the bottom wall of the support 11 are four holes 16.1 and one hole 16.2. The axes of the holes 16.1 are each aligned with the vertices of the perimeter of the track 12, while the axis of the hole 16.2 is aligned with the intersection of the diagonals of the perimeter of this said track.

    [0026] Each hole 16.1, 16.2 houses a respective moveable peg 17.1, 17.2 (Fig. 6) that can be placed in two different positions with respect to the support 11, one being a working position (Fig. 7) and the other a rest position (Fig. 8), corresponding to the peg being pushed in or pulled out manually, respectively.

    [0027] Eight modified tiles denoted 14' have in their head 14.2' a cutout 14.3 of essentially cylindrical surface.

    [0028] In its rest position, each peg 17.1, 17.2 does not emerge into the track 12 and therefore does not interfere with the movement of the tiles 14.

    [0029] However, in their working position the pegs 17.1 emerge into their respective corners of the track 12, preventing the head 14.2 of an ordinary tile 14 from occupying a position corresponding to these corners. The corner positions can instead be occupied only by four modified tiles 14' correctly oriented in such a way that the head of each with the cutout 14.3 is juxtaposed correctly against a respective peg 17.1.

    [0030] Similarly the peg 17.2 in its working position emerges in the centre of the track 12, preventing four ordinary tiles 14 from occupying the central position of the track. The centre of the said track 12 can instead be occupied only by four modified tiles 14', correctly oriented in such a way that their heads with the cutouts 14.3 are juxtaposed correctly around the said peg 17.2.

    [0031] The working position of play of the pegs 17.1 raises the difficulty of the game (difficulty level 2) compared with their rest condition (difficulty level 1). The difficulty of the game is even greater (difficulty level 3) if the central peg 17.2 is in the working position, while the pegs 17.1 are in the rest position.

    [0032] It goes without saying that the four pegs 17.1 or the peg 17.2 can be made fixed. In this case the difficulty level of the game device cannot be modified.

    [0033] To ensure the correct play position of the pegs 17.1, 17.2, the latter have a head which, in the working position, is juxtaposed against the board 11, while a spring ring 17.4 is mounted on the body of the peg, thus increasing the friction against the wall of the corresponding housing hole.


    Claims

    1. Educational game device with sliding tiles to arrange in predetermined sequences, comprising a support or board (11) , and, in the said support (11), two mutually adjacent and communicating tracks (12, 13), a principal track (12) having greater area and an auxiliary track (13) of smaller area, and wherein at the beginning and end of the game the principal track (12) is completely occupied by a plurality of tiles (14) positioned side by side in an arrangement of rows and columns, each tile (14) being able to slide in perpendicular directions, characterized in that the auxiliary track (13) is occupied only partly by a block (15) that is able to slide in only one direction parallel to one direction of sliding of the said tiles (14) between two positions of play, in each of which the said block (15) leaves in the said auxiliary track (13) an unoccupied space (15.3) of variable position and of dimensions approximately corresponding to the dimensions of one tile (14), so that in each of the said two positions of play of the block (15) a respective tile (14) in the row of tiles adjacent to the auxiliary track (13) is next to the said unoccupied space (15.3), which this tile can be made to occupy by sliding it in a direction perpendicular to that of the said block (15), thereby opening up in the principal track (12) a corresponding unoccupied space between the tiles (14), which - during the game - can be rearranged relative to each other in the principal track (12) by movements in perpendicular directions.
     
    2. Game device according to Claim 1, characterized in that the said principal track (12) comprises a network of longitudinal (12.1) and transverse (12.2) straight perpendicular intersecting slideways, while the said auxiliary track (13) comprises a single straight slideway (13.1) that is parallel to the said longitudinal ways (12.1) and lies between two transverse ways (12.2), with which this way (13.1) communicates at its ends.
     
    3. Game device according to Claim 2, characterized in that at the beginning and end of the game each tile (14) is arranged in the principal track (12) at its own intersection between a longitudinal way (12.1) and a transverse way (12.2).
     
    4. Game device according to Claim 1, characterized in that the said principal track (12) is basically quadrilateral and the said tiles (14) have one face visible from the outside that is at least partly coloured, so that at the beginning of the game the said adjacent tiles form, in the corners of the track (12), a geometrical arrangement of four identical right-angled triangles having mirror symmetry and having the same colour, and in the centre of the track a rhombus whose sides coincide with the hypotenuses of the four right-angled triangles (Fig. 1), while the object of the game is, by moving the said tiles (14) and the said block (15), to exchange the colour of the rhombus with that of the right-angled triangles inscribed within said track (12) (Fig. 2).
     
    5. Game device according to Claim 1 or 4, characterized in that the said tiles (14) each comprise an external face having a surface that is at least partly irregular, for example knurled or provided with depressions and/or reliefs, so that the game device can also be used by the visually disabled.
     
    6. Game device according to one or more of the preceding claims, characterized in that it comprises at least one peg (17.1, 17.2) that prevents any of the said tiles (14) from correctly occupying the position corresponding to it in the said track (12), and in that it comprises at least one modified tile (14') (cutout 14.3) so that it can be placed against said peg and correctly occupy the position corresponding to that peg in the principal track (12).
     
    7. Game device according to Claim 6, characterized in that it comprises at least one moveable peg (17.1, 17.2) that can be moved between two different positions with respect to the said principal track (12), a rest position and a working position, in which working position it prevents any of the said tiles (14) from correctly occupying the position corresponding to the said peg in the said track (12), and in that it comprises at least one modified tile (14') (cutout 14.3) so that it can be placed against said peg and correctly occupy the position corresponding to that peg in the principal track (12).
     
    8. Game device according to Claim 7, in which the said principal track (12) is basically quadrilateral, characterized in that it comprises five moveable pegs (17.1, 17.2) arranged respectively in the four corners and in the centre of the said principal track (12), and eight modified tiles (14'), so that the difficulty of the game can be increased, from the rest situation of the said pegs (difficulty level 1), by bringing into the working position the pegs (17.1) that are in the corners of the said track (12) (difficulty level 2), or still further increased by placing the central peg (17.2) in the working position (difficulty level 3), while the pegs (17.1) that are in the corners of the said principal track (12) are at rest.
     


    Ansprüche

    1. Lernspielvorrichtung zum Anordnen verschiebbarer Platten in bestimmten Reihenfolgen mit einem Träger oder Brett (11) und in dem Träger (11) zwei gegenseitig benachbarten und miteinander verbundenen Spuren (12, 13), einer Hauptspur (12) mit einer größeren Fläche und einer Nebenspur (13) mit einer kleineren Fläche, und wobei zu Beginn und am Ende des Spiels die Hauptspur (12) von mehreren Platten (14) vollständig besetzt ist, die Seite an Seite in einer Reihen- und Spaltenanordnung angeordnet sind, wobei jede Platte (14) in senkrechten Richtungen verschiebbar ist,
    dadurch gekennzeichnet, dass
    die Nebenspur (13) nur teilweise von einem Block (15) besetzt ist, der nur in einer Richtung parallel zu einer Verschieberichtung der Platten (14) zwischen zwei Spielstellungen verschiebbar ist, wobei der Block (15) in jeder davon in der Nebenspur (13) einen unbesetzten Raum (15.3) in einer veränderbaren Stellung und mit Abmessungen etwa entsprechend den Abmessungen einer Platte (14) zurücklässt, so dass in jeder der beiden Spielstellungen des Blocks (15) eine entsprechende Platte (14) in der Plattenreihe neben der Nebenspur (13) neben dem unbesetzten Raum (15.3) liegt, der durch diese Platte durch ihr Verschieben in einer Richtung senkrecht zu der des Blocks (15) besetzt werden kann, wodurch in der Hauptspur (12) ein entsprechender unbesetzter Raum zwischen den Platten (14) geöffnet wird, der - während des Spiels - durch Bewegungen in senkrechten Richtungen in der Hauptspur (12) zueinander neu angeordnet werden kann.
     
    2. Spielvorrichtung nach Anspruch 1, dadurch gekennzeichnet, dass die Hauptspur (12) ein Netz aus länglichen (12.1) und querlaufenden (12.2), geraden, senkrecht sich schneidenden Verschiebewegen umfasst, während die Nebenspur (13) einen einzigen geraden Verschiebeweg (13.1) umfasst, der parallel zu den Längswegen (12.1) verläuft und zwischen zwei Querwegen (12.2) liegt, mit dem dieser Weg (13.1) an seinen Enden in Verbindung steht.
     
    3. Spielvorrichtung nach Anspruch 2, dadurch gekennzeichnet, dass zu Beginn und am Ende des Spiels jede Platte (14) in der Hauptspur (12) an ihrem eigenen Schnittpunkt zwischen einem Längs- (12.1) und einem Querweg (12.2) angeordnet ist.
     
    4. Spielvorrichtung nach Anspruch 1, dadurch gekennzeichnet, dass die Hauptspur (12) grundsätzlich vierseitig ist und die Platten (14) eine von außen sichtbare Fläche haben, die mindestens teilweise farbig ist, so dass die benachbarten Platten zu Beginn des Spiels in den Ecken der Spur (12) eine geometrische Anordnung aus vier identischen rechtwinkligen Dreiecken mit gespiegelter Symmetrie und derselben Farbe und in der Mitte der Spur einen Rhombus bilden, dessen Seiten mit den Hypotenusen der vier rechtwinkligen Dreiecke (Fig. 1) deckungsgleich sind, während das Ziel des Spieles darin besteht, durch Bewegen der Platten (14) und des Blocks (15) die Farbe des Rhombus mit der der rechtwinkligen Dreiecke zu tauschen, die innerhalb der Spur (12) (Fig. 2) gebildet werden.
     
    5. Spielvorrichtung nach Anspruch 1 oder 4, dadurch gekennzeichnet, dass die Platten (14) jeweils eine Außenseite umfassen, die mit einer Oberfläche ausgestattet ist, die mindestens teilweise unregelmäßig, zum Beispiel gerändelt, oder mit Vertiefungen und/oder Senken versehen ist, so dass die Spielvorrichtung auch von sehbehinderten Menschen benutzt werden kann.
     
    6. Spielvorrichtung nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass sie mindestens einen Stöpsel (17.1, 17.2) umfasst, der verhindert, dass eine der Platten (14) die ihr entsprechende Stellung in der Spur (12) vollständig besetzt, und dass sie mindestens eine veränderte Platte (14') (Ausschnitt 14.3) umfasst, so dass sie gegen den Stöpsel angeordnet werden kann und die diesem Stöpsel entsprechende Stellung in der Hauptspur (12) vollständig besetzen kann.
     
    7. Spielvorrichtung nach Anspruch 6, dadurch gekennzeichnet, dass sie mindestens einen beweglichen Stöpsel (17.1, 17.2) umfasst, der zwischen zwei unterschiedlichen Stellungen gegenüber der Hauptspur (12), einer Ruhestellung und einer Arbeitsstellung, bewegt werden kann, wobei sie in der Arbeitsstellung verhindert, dass eine der Platten (14) die Stellung entsprechend dem Stöpsel in der Spur (12) vollständig besetzen kann, und dass sie mindestens eine veränderte Platte (14') (Ausschnitt 14.3) umfasst, so dass sie gegen den Stöpsel angeordnet werden kann und die dem Stöpsel entsprechende Stellung in der Hauptspur (12) vollständig besetzen kann.
     
    8. Spielvorrichtung nach Anspruch 7, in dem die Hauptspur (12) grundsätzlich vierseitig ist, dadurch gekennzeichnet, dass sie fünf bewegliche Stöpsel (17.1, 17.2), die jeweils in den vier Ecken und in dem Zentrum der Hauptspur (12) angeordnet sind, und acht veränderte Platten (14') umfasst, so dass die Schwierigkeitsstufe des Spiels erhöht werden kann, nämlich aus der Ruhestellung der Stöpsel (Schwierigkeitsgrad 1), indem die Stöpsel (17.1), die sich in den Ecken der Spur (12) befinden (Schwierigkeitsgrad 2), in die Arbeitsstellung gebracht werden, oder noch weiter erhöht werden kann, indem der mittige Stöpsel (17.2) in die Arbeitsstellung (Schwierigkeitsgrad 3) gebracht wird, während die Stöpsel (17.1), die sich in den Ecken der Hauptspur (12) befinden, im Ruhezustand sind.
     


    Revendications

    1. Dispositif de jeu éducatif avec des carrés coulissants pour être disposés en séquences prédéterminées, comprenant un support ou carte (11) et dans ledit support (11) deux pistes communicantes et mutuellement adjacentes (12, 13), une piste principale (12) ayant une surface plus grande et une piste auxiliaire (13) ayant une surface plus petite et dans lequel au début et à la fin du jeu, la piste principale (12) est complètement occupée par une pluralité de carrés (14) positionnés côte à côte dans une disposition en rangée et en colonne, chaque carré (14) pouvant glisser dans des directions perpendiculaires, caractérisé en ce que la piste auxiliaire (13) est partiellement occupée seulement par un bloc (15) qui est capable de coulisser seulement dans une direction parallèle à une direction de coulissement desdits carrés (14) entre deux positions de jeu, dans chacune desquelles ledit bloc (15) quitte dans ladite piste auxiliaire (13) un espace inoccupé (15.3) de position variable et de dimension correspondant approximativement aux dimensions d'un carré (14) de sorte que dans chacune desdites deux positions de jeu du bloc (15) un carré respectif (14) dans la rangée de carrés adjacente à la piste auxiliaire (13) est le prochain dans ledit espace inoccupé (15.3), carré qui peut être amené à occuper en coulissant le carré dans une direction perpendiculaire à celle dudit bloc (15), ouvrant ainsi dans la piste principale (12) un espace inoccupé correspondant entre les carrés (14), qui peuvent être redisposés les uns aux autres pendant le jeu dans la piste principale (12) par des déplacements dans des directions perpendiculaires.
     
    2. Dispositif de jeu selon la revendication 1, caractérisé en ce que ladite piste principale (12) comprend un réseau de glissières interconnectées perpendiculaires droites transversales (12.2) et longitudinales (12.1) tandis que la piste auxiliaire (13) comprend une seule glissière droite (13.1) qui est parallèle auxdites glissières longitudinales (12.1) et qui se trouve entre deux glissières transversales (12.2) avec lesquels cette glissière (13.1) communique à ses extrémités.
     
    3. Dispositif de jeu selon la revendication 2, caractérisé en ce qu'au début et à la fin du jeu, chaque carré (14) est disposé dans la piste principale (12) à sa propre intersection entre une glissière longitudinale (12.1) et une glissière transversale (12.2).
     
    4. Dispositif de jeu selon la revendication 1, caractérisé en ce que ladite piste principale (12) est basiquement quadrilatère et lesdits carrés (14) ont une face visible de l'extérieur qui est au moins partiellement colorée de sorte qu'au début du jeu, lesdits carrés adjacents forment dans les coins de la piste (12) une structure géométrique de quatre triangles rectangles identiques ayant une symétrie inversée et ayant la même couleur et au centre de la piste, un rhombus dont les côtés coïncident avec les hypoténuses des quatre triangles rectangles (Figure 1) tandis que l'objet du jeu est par déplacement desdits carrés (14) et dudit bloc (15) d'échanger la couleur du rhombus avec celle des triangles rectangles inscrits à l'intérieur de ladite piste (12) (figure 2).
     
    5. Dispositif de jeu selon la revendication 1 ou 4, caractérisé en ce que lesdits carrés (14) comprennent chacun une face externe ayant une surface qui est au moins partiellement irrégulière, par exemple moletée ou munie de dépressions et/ou de reliefs de sorte que le dispositif de jeu puissent être également utilisé par des malvoyants.
     
    6. Dispositif de jeu selon une ou plusieurs des revendications précédentes, caractérisé en ce qu'il comprend au moins un tenon (17.1, 17.2) qui empêche chaque carré (14) de se positionner correctement dans la position qui leur correspond dans ladite piste (12) et en ce qu'il comprend au moins un carré modifié (14') (détouré 14.3) de sorte q'il peut être placé contre ledit tenon et occuper correctement la position correspondant à ce tenon dans la piste principale (12).
     
    7. Dispositif de jeu selon la revendication 6, caractérisé en ce qu'il comprend au moins un tenon mobile (17.1, 17.2) qui peut être déplacé entre deux positions différentes par rapport à ladite piste principale (12), à savoir une position de repos et une position de travail, position de travail dans laquelle il empêche chaque dit pavé (14) d'occuper correctement la position correspondant audit tenon dans ladite piste (12) et en ce qu'il comprend au moins un carré modifié (14') (détouré 14.3) de sorte q'il peut être placé contre ledit tenon et occuper correctement la position correspondant au tenon dans la piste principale (12).
     
    8. Dispositif de jeu selon la revendication 7, dans lequel ladite piste principale (12) est basiquement quadrilatère caractérisé en ce qu'il comprend 5 tenons mobiles (17.1, 17.2) disposés respectivement dans les quatre coins et au centre de ladite piste principale (12) et huit carrés modifiés (14')de sorte que la difficulté du jeu peut être augmentée, de la situation de repos desdits tenons (niveau de difficulté 1) en amenant en position de travail les tenons (17.1) qui sont dans les coins de ladite piste (12) (niveau de difficulté 2) en plaçant le tenon central (17.2) dans la position de travail (niveau de difficulté 3) tandis que les tenons (17.1) qui sont dans les coins de ladite piste principale (12) sont au repos.
     




    Drawing