SNOWPLOW BLADE

Description

TECHNICAL FIELD

[0001] The present invention relates to a snowplow blade adapted to be driven by a self-propelled unit to remove snow or ice from a surface to be cleared, for example a road surface, to which the ensuing treatment will make explicit reference, without this implying any loss in generality.

BACKGROUND ART

[0002] In particular, the present invention relates to a snowplow blade of the type comprising a mounting frame to the self-propelled unit, an upper rolling element coupled to the mounting frame and a lower road surface scraping knife. The known blades of the type described above operate in a satisfactory manner when the road surface is flat, whereas they are found to be poorly efficient when the road surface has concavities and/or convexities or longitudinal bumps. In fact, in presence of non-flat road surfaces, indicated in the jargon as "horseback surfaces", a segment or segments of the straight lower edge of the knife slide in contact with the raised portions of the surface, other segments remain vertically separated from other corresponding lower portions of the surface itself inevitably leaving on the lower portions themselves a layer of compacted

[0003] snow intolerable for security issues. Document WO2011/123956 A1 discloses snowplow blade comprising an upper rolling element and a lower road surface scraping knife. The scraping knife, in turn, comprises a plurality of plate like portions arranged closed to each other and each sliding in a substantially vertically direction with respect a upper rolling element.

[0004] This solution does not enable to obtain an accurate cleaning of the road surface, i.e to clean in the same way all the zones of the surface to be cleaned.

DISCLOSURE OF INVENTION

[0005] An object of the present invention is to obtain a snowplow blade, which allows to solve in a simple and economical way the above exposed problems and, in particular, to obtain a uniform clearing of the road surface independently from the state of the road surface itself.

[0006] According to the present invention a snowplow blade is obtained, as claimed in Claim 1.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The invention is now described with reference to the accompanying drawings, which illustrate a nonlimiting embodiment, wherein:

Figure 1 is a perspective view of a preferred embodiment of a snowplow blade obtained according to the dictates of the present invention coupled to a thrust tractor;

Figure 2 illustrates, in side elevation and on an enlarged scale with parts removed for clarity, the snowplow blade of Figure 1;

Figure 3 illustrates, in section and on an enlarged scale, a detail of Figure 2;

Figure 4 is a front view with parts removed for clarity of the snowplow blade of Figure 1;

Figure 5 is an enlarged perspective view of a detail of Figures 3 and 4; and

Figure 6 is a figure similar to Figure 3 and illustrates a variant of a detail of Figure 3.

BEST MODE FOR CARRYING OUT THE INVENTION

[0008] In Figure 1, 1 indicates, as a whole, a snowplow blade adapted to be advanced above a surface 2 to be cleared, generally a road surface or a square, by a self-propelled unit 3, schematically illustrated and known per se.

[0009] The blade 1 comprises a mounting frame 4 to the self-propelled unit,3, an elongated rolling element 5, known per se and not described in detail, coupled to the frame 4 in a rotating manner about an axis 7 substantially orthogonal to the surface 2 under the thrust of actuators 6.

[0010] The blade 1 also comprises a pair of support wheels or vertical reference, known per se and not visible in the attached figures, disposed in the vicinity of the frame 4 and in the rear of the rolling element 5 to rotate in contact with the surface 2 cleared by blade 1.

[0011] The blade 1 comprises, finally, an elongated knife 8, which is disposed below the rolling element, constitutes a downward extension of the rolling element 5 and terminates below with a sliding edge 9, in use, in contact with the surface 2.

[0012] As can be seen from Figures 1 and 4, the knife 8 is constituted by a row 10 of modules 11 independent from one another and juxtaposed one to the other.

[0013] Each module 11 comprises a flat elongated plate 12, which is conveniently made of metallic material and, in a scraping condition, illustrated in Figures 1 to 3, is juxtaposed and aligned to the other plates 12 in a rectilinear direction 13 (Fig. 1) transverse to an advancement direction of the blade 1, orthogonal to the axis 7 and substantially parallel to a generatrix of the rolling element 5 to define a portion of the knife 8.

[0014] Each module 11 comprises, furthermore, a supporting guide and slide assembly 15 thereof of the respective plate 12 and a mounting plate block 16, elastically yielding, of the assembly 15 to the rolling element. In particular, each block 16 has an upper end firmly connected to a lower end portion of the rolling element 5 by means of respective bolts 18 and a lower end firmly connected to the guide and slide assembly 15 by means of respective bolts 19. Each plate block 16 is dimensioned so as to maintain the relative plate 12 in a scraping operative advanced position, illustrated in Figures 1 and 4, and to allow the backward rotation of the relative assembly 15 and of the relative plate 12 with respect to the rolling element 5 about a hinge axis 20 parallel to the rectilinear direction 13 and orthogonal to axis 7 when the plate 12 meets on the surface 2 a fixed located obstacle.

[0015] According to a variation not illustrated, each block 16 is replaced by a mechanical hinge and a forcing elastic element and preloaded the hinge to maintain the plate in the scraping operative position.

[0016] Still with reference to Figures 1 and 2 and, in particular, to Figure 3, each assembly 15 comprises a flat rear metal plate 22 disposed partially in abutment on a front surface of the respective block 16 and a flat front metal plate 23 disposed parallel one another and spaced from each other by an upper spacer 24 of an amount approximately rounded up to the thickness of the relative plate 12.

[0017] The plates 22 and 23 the spacer 24 and the block 16 are pack-tightened one another by the bolts 19. The plates 22 and 23, the spacer 24 and the block 16 delimit one another a seat 27 open downwards, in which an upper portion 12a of the relative plate 12 is slidably inserted, the remaining portion 12b thereof projects downwards in a cantilever manner beyond the plates 22 e 23 themselves.

[0018] Each assembly 15 comprises, furthermore, a further row of bolts 28 disposed below the bolts 19 and crossing both plates 22 and 23. Each bolt 28 also crosses a respective slot 30, which is elongated in a substantially vertical direction and is attained in the upper portion 12a of the plate 12. Preferably, each slot has a length measured in a substantially vertical direction variable between 15 and 35 millimeters, conveniently 20 millimeters, and houses with radial play a respective bushing or sleeve 31, in turn crossed with radial play by the stem of the respective bolt 28.

[0019] With explicit reference to Figure 4, each upper portion 12a is delimited on the side facing the spacer 24 by a peripheral surface 33, which delimits with the spacer 24 itself and with part of the plates 22 and 23 an elongated chamber 35, in which a plurality of elastic bodies 36 conveniently made of a single piece of elastomeric material is housed, preferably a polyurethane material and independent from one another.

[0020] Each elastic body 36 is retained in an operative position thereof, spaced from the other bodies 36 by prominences 37 protruding, in the particular example described, both from -the plate 12 and from the spacer 24.

[0021] Also in the particular example described, each body 36 has an inverted eight shape and comprises two tubular portions 39, which are connected one another by a transverse arm 40 and have respective axes 41 orthogonal to the plates 12,22 and 23 and parallel one another and to bolts 18,19 and 28.

[0022] The tubular portions 39 have outer diameters greater than the maximum distance d (Fig. 4) of the surface 33 from the spacer 24 so as to push and maintain the respective plate 12 in an extracted position and the bushings 31, together with the stems of the bolts 28 to the upper end of the relative slots 30 (Figure 4).

[0023] According to variations not shown, the bodies 36 of elastomeric material are not made in one piece have different geometries with respect to that indicated by way of example, or are in whole or in part replaced by other elastic elements such as, for example, coil compression springs or leaf springs or other equivalent component elastically yielding.

[0024] In use, i.e. when the plates 12 scrape the surface 2, the elastic bodies 36, independently of whether elastomeric or metal or a combination thereof, by deforming elastically each, according to the action received from the respective underlying portion of the plate 12 allow the plate 12 itself to translate or slide within the seat 27 towards the rolling element 5 in a substantially rectilinear direction and/or rotate with respect to the plates 22 and 23 for coupling effect with the play of the plates 22 and 23 themselves to the respective bolts 28, about an instantaneous rotation axis orthogonal to the plates 12, 22 and 23 and substantially parallel to the bolts 19 and 28.

[0025] In this way, each plate 12 according to the entity of the thrust received by the underlying portion of the surface 12 determined by the geometry of the portion of the surface itself moves with respect to the rolling element 5 and with respect to the other plates 22 and 23 and following the profile of the surface 12 so that, in use, the lower edge 9 of the knife 8 is found to be rectilinear in case the knife 8 itself slides on a flat surface and at a broken curve when it slides in contact with convex or bumpy surfaces. In both cases, the knife 8 adapting to the geometry of the surface 12 to be cleared clears in the same way any area of the surface 12 itself.

[0026] According to a first variant, each block 16 is a rigid block adapted to connect permanently and integrally the respective assembly 15 to the rolling element 5. Alternatively, each plate 22 is directly and permanently connected to the rolling element 8.

[0027] In both cases, between the rolling element 5 and the frame 4 elastically yielding means are provided, and known per se, adapted to allow the backward rotation of the rolling element 5 together with the knife 8 about a hinge, axis practically parallel to the rectilinear direction 13 when the knife 8 meets on the surface 2 a fixed located obstacle.

[0028] According to a further variant illustrated in Figure 6, the blocks 16 are replaced by a rigid load-bearing or support structure 45, which is common to, and supports all, assemblies 15, and is hinged to the rolling element 5 by means of a hinge 46 elastically preloaded by an elastic device, preferably with wire springs or elastomeric material, generically indicated with 48, to maintain the structure 45 in a reference or limit operating advanced position and allow the structure 45 itself and to the plates 9 to rotate simultaneously backwards with respect to the rolling element 5 about a common hinge axis 47 parallel to the rectilinear direction 13 in the presence of fixed obstacles on the surface 2 to be cleared.

[0029] From the foregoing it will be evident that the blade 1 described may be made to further modifications and variations which do not depart from the protective scope defined by the independent claim.- In particular, the knife 8 could include a number of modules or plates 9 different from that illustrated and for example only two modules and therefore also only two independent plates, although it is obvious that the greater the number of plates 12 the better the knife edge 8 approximates the curvature of the surface 2 and the more accurate is the clearing of the surface 2 itself.

[0030] Finally, at least part of the guide and slide devices 15 may be shaped so as to allow only the translation of the relative plate 12 from and to the rolling element 5.

[0031] In particular, the plates 12 may be coupled to the rolling element 5 in order to translate or slide only from and to the rolling element 5 itself. In this condition, the lower edge of the knife 8 approximates, in use, the curvature of the surface 12 to be cleared, thereby clearing the surface 12 in a rough but still acceptable manner. Obviously, both in such condition and in the case of roto-translation of the blades 12 above described, the clearing of the surface 12 is much better, the greater the number of units 11 and therefore the greater the number of plates 12.

Claims

1. A snowplow blade (1) comprising a mounting frame (4) to a self-propelled advancement unit (3) of the blade itself above a surface (2) to be cleared, an upper elongated rolling element (5) carried by said frame (4) and an elongate lower knife (8) constituting a downwards extension of the upper rolling element (5) and having a free sliding lower edge (9), in use, in contact with said surface (2) to be cleared; the lower knife (8) comprising at least two elongated plate portions (12) independent of one another and aligned in a direction transverse (13) to the advancement direction of the blade (1); and, for each of said elongated plate portion (12), at least a respective guide and slide assembly (15) adapted to allow at least a translation of the respective said elongated plate portion (12) to and from said rolling element (5) with respect to the other of said elongated plate portions (12) and elastic thrust means (36) interposed between each of said elongated plate portion (12) and the rolling element (5) to space the elongated plate portion (12) from the rolling element (5), characterized by comprising, in addition, for each of said elongated plate portion (12), at least one respective hinge adapted to allow, in use, a rotation of the respective said elongated plate portion (12) with respect to the other of said elongated plate portions (12) about an axis of instantaneous rotation substantially orthogonal to the respective said elongated plate portion (12).

2. The blade according to claim 1, characterized by comprising, for each of said elongated plate portion (12), at least one pair of said guide and slide assemblies (15) spaced from one another along the respective elongated plate portion (12) in said transverse direction (13).

3. The blade according to claim 1 or 2, characterized by comprising one of said hinges for each of said guide and slide assembly (15).

4. The blade according to any preceding claims, characterized in that said elastic thrust means (36) retain the respective said elongated plate portion (12) in an extracted limit position.

5. The blade according to any preceding claims, characterized in that said elastic means (36) comprise at least one block (36) of elastically deformable material forced between a terminal edge of the respective elongated plate portion (12) and a reference body carried by said rolling element (5).

6. The blade according to claim 5, characterized in that said block (36) of elastically deformable material is forced between an upper end surface of the respective said elongated plate portion (12) and an abutment surface of the said reference body.

7. The blade according to claim 5 or 6, characterized in that said elastic means comprise, for each of said elongated plate portion (12), a plurality of said blocks (36) of elastically deformable material distributed along the length of said elongated plate portion (12).

8. The blade according to claim 6 or 7, characterized in that each of said block (36) comprises at least one tubular portion (39) having an axis (41) orthogonal to the respective said elongated plate portion (12).

9. The blade according to any preceding claims, characterized in that each of said guide and slide assembly (15) comprises two guide plates (22)(23) substantially flat, parallel and facing one another accommodating between each other in a sliding manner a flat upper end segment of the respective said elongated plate portion (12), a first (22) of said plates (22)(23) being connected to said rolling element (5).

10. The blade according to claim 9, characterized in that each of said guide and slide assembly (15) also comprises a respective reference pin (28,31) carried by one of said plates and a slot (30) formed on said plate portion (12) and engaged with clearance by said pin (28,31).

11. The blade according to claim 9 or 10, characterized by comprising, furthermore, hinge means (16) interposed between said rolling element (5) and said first plate (22) to allow the respective said elongated plate portion (12) to rotate backwards with respect to the rolling element (5) around a hinge axis (20) parallel to said transverse direction independently of the other elongated plate portions (12).

12. The blade according to claim 9 or 10, characterized in that said first plate (22) is integrally connected to said rolling element (5).

13. The blade according to claim 9 or 10, characterized in that said first plates (22) are carried by a common support structure (45), and in that it also comprises additional hinge means (46) interposed between said rolling element (5) and said common support structure (45) to allow said elongated plate portions (12) to simultaneously rotate with respect to the rolling element (5) around a common hinge axis (47) parallel to said transverse direction; elastic means (48) being provided for maintaining said common structure (45) in an angular reference position.

14. The blade according to any preceding claims, characterized in that said knife (8) comprises a plurality of said elongated plate portions (12) independent from one another.

Ansprüche

1. Schild (1) für einen Schneepflug, umfassend einen Befestigungsrahmen (4) für eine mit Eigenantrieb versehene Vorwärtsbewegungseinheit (3) für das Schild selbst über einer zu räumenden Oberfläche (2), ein oberes längliches Rollelement (5), das von dem Rahmen (4) getragen wird, und eine längliche untere Klinge (8), die eine Abwärtsverlängerung des oberen Rollelements (5) darstellt und eine frei verschiebbare untere Kante (9) aufweist, die im Gebrauch die zu räumende Oberfläche (2) berührt; wobei die untere Klinge (8) mindestens zwei längliche Plattenabschnitte (12) umfasst, die voneinander unabhängig sind und in einer Richtung (13) quer zur Vorwärtsbewegungsrichtung des Schilds (1) ausgerichtet sind; sowie, für jeden der länglichen Plattenabschnitte (12), mindestens eine jeweilige Führungs- und Verschiebebaugruppe (15), die so ausgelegt ist, dass sie zumindest eine Parallelverschiebung des jeweiligen länglichen Plattenabschnitts (12) zum Rollelement (5) hin und davon weg bezogen auf den anderen der länglichen Plattenabschnitte (12) zulässt, und elastische Schubmittel (36), die zwischen jedem der länglichen Plattenabschnitte (12) und dem Rollelement (5) angeordnet sind, damit der längliche Plattenabschnitt (12) einen Abstand zum Rollelement (5) aufweist, dadurch gekennzeichnet, dass es, für jeden der länglichen Plattenabschnitte (12), zusätzlich mindestens ein jeweiliges Scharnier umfasst, das so ausgelegt ist, dass es im Gebrauch eine Drehbewegung des jeweiligen länglichen Plattenabschnitts (12) bezogen auf den anderen der länglichen Plattenabschnitte (12) um eine momentane Drehachse im Wesentlichen rechtwinklig zum jeweiligen länglichen Plattenabschnitt (12) zulässt.

2. Schild nach Anspruch 1, dadurch gekennzeichnet, dass es, für jeden der länglichen Plattenabschnitte (12), mindestens ein Paar der Führungs- und Verschiebebaugruppen (15) umfasst, die entlang des jeweiligen länglichen Plattenabschnitts (12) in der Querrichtung (13) einen Abstand zueinander aufweisen.

3. Schild nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass es eines der Scharniere für jede Führungs- und Verschiebebaugruppe (15) umfasst.

4. Schild nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die elastischen Schubmittel (36) den jeweiligen länglichen Plattenabschnitt (12) in einer herausgezogenen Endstellung halten.

5. Schild nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die Schubmittel (36) mindestens einen Block (36) aus elastisch verformbarem Material umfassen, der zwischen einer Endkante des jeweiligen länglichen Plattenabschnitts (12) und einem Bezugskörper, der von dem Rollelement (5) getragen wird, eingeklemmt ist.

6. Schild nach Anspruch 5, dadurch gekennzeichnet, dass der Block (36) aus elastisch verformbarem Material zwischen einer oberen Endfläche des jeweiligen länglichen Plattenabschnitts (12) und einer Anlagefläche des Bezugskörpers eingeklemmt ist.

7. Schild nach Anspruch 5 oder 6, dadurch gekennzeichnet, dass die elastischen Mittel, für jeden der länglichen Plattenabschnitte (12), mehrere der Blöcke (36) aus elastisch verformbarem Material umfassen, die entlang der Länge des länglichen Plattenabschnitts (12) verteilt sind.

8. Schild nach Anspruch 6 oder 7, dadurch gekennzeichnet, dass jeder Block (36) mindestens einen röhrenförmigen Abschnitt (39) mit einer Achse (41) rechtwinklig zum jeweiligen länglichen Plattenabschnitt (12) umfasst.

9. Schild nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass jede Führungs- und Verschiebebaugruppe (15) zwei im Wesentlichen ebene, parallel verlaufende und einander zugewandte Führungsplatten (22) (23) umfasst, die dazwischen verschiebbar ein ebenes oberes Endsegment des jeweiligen länglichen Plattenabschnitts (12) aufnehmen, wobei eine erste (22) der Platten (22) (23) mit dem Rollelement (5) verbunden ist.

10. Schild nach Anspruch 9, dadurch gekennzeichnet, dass jede Führungs- und Verschiebebaugruppe (15) auch einen jeweiligen Bezugsstift (28, 31) umfasst, der von einer der Platten getragen wird, und einen Schlitz (30), der an dem Plattenabschnitt (12) ausgebildet ist und in den der Stift (28, 31) mit Spiel eingreift.

11. Schild nach Anspruch 9 oder 10, dadurch gekennzeichnet, dass es ferner Scharniermittel (16) umfasst, die zwischen dem Rollelement (5) und der ersten Platte (22) angeordnet sind, damit der jeweilige längliche Plattenabschnitt (12) bezogen auf das Rollelement (5) um eine Gelenkachse (20) parallel zu der Querrichtung unabhängig von den anderen länglichen Plattenabschnitten (12) nach hinten drehbar ist.

12. Schild nach Anspruch 9 oder 10, dadurch gekennzeichnet, dass die erste Platte (22) einteilig mit dem Rollelement (5) verbunden ist.

13. Schild nach Anspruch 9 oder 10, dadurch gekennzeichnet, dass die ersten Platten (22) von einer gemeinsamen Trägerstruktur (45) getragen werden, und dadurch, dass es auch zusätzliche Scharniermittel (46) umfasst, die zwischen dem Rollelement (5) und der gemeinsamen Trägerstruktur (45) angeordnet sind, damit die länglichen Plattenabschnitte (12) bezogen auf das Rollelement (5) gleichzeitig um eine gemeinsame Gelenkachse (47) parallel zu der Querrichtung drehbar sind; wobei elastische Mittel (48) zum Halten der gemeinsamen Struktur (45) in einer Winkelbezugsstellung vorgesehen sind.

14. Schild nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die Klinge (8) mehrere der länglichen Plattenabschnitte (12) unabhängig voneinander umfasst.

Revendications

1. Lame de chasse-neige (1) comprenant un bâti de montage (4) sur une unité d'avancement autopropulsée (3) de la lame elle-même au-dessus d'une surface (2) à dégager, un élément roulant allongé supérieur (5) porté par ledit bâti (4) et un couteau inférieur allongé (8) constituant une extension descendante de l'élément roulant supérieur (5) et ayant un bord inférieur coulissant libre (9), à l'usage, en contact avec ladite surface (2) à dégager ; le couteau inférieur (8) comprenant au moins deux parties de plaque allongées (12) indépendantes l'une de l'autre et alignées dans une direction transversale (13) par rapport à la direction d'avancement de la lame (1) ; et, pour chacune desdites parties de plaque allongées (12), au moins un ensemble de guidage et de coulissement respectif (15) adapté pour permettre au moins une translation de ladite partie de plaque allongée (12) respective vers et depuis ledit élément roulant (5) par rapport à l'autre desdites parties de plaque allongées (12) et un moyen de poussée élastique (36) intercalé entre chacune desdites parties de plaque allongées (12) et l'élément roulant (5) pour éloigner la partie de plaque allongée (12) de l'élément roulant (5), caractérisé en ce qu'elle comprend, en outre, pour chacune desdites parties de plaque allongées (12), au moins une charnière respective adaptée pour permettre, à l'usage, une rotation de ladite partie de plaque allongée (12) respective par rapport à l'autre desdites parties de plaque allongées (12) autour d'un axe de rotation instantanée sensiblement orthogonal à ladite partie de plaque allongée (12) respective.

2. Lame selon la revendication 1, caractérisée en ce qu'elle comprend, pour chacune desdites parties de plaque allongées (12), au moins une paire desdits ensembles de guidage et de coulissement (15) espacés l'un de l'autre le long de la partie de plaque allongée (12) respective dans ladite direction transversale (13).

3. Lame selon la revendication 1 ou 2, caractérisée en ce qu'elle comprend l'une desdites charnières pour chacun desdits ensembles de guidage et de coulissement (15).

4. Lame selon l'une quelconque des revendications précédentes, caractérisée en ce que lesdits moyens de poussée élastiques (36) retiennent ladite partie de plaque allongée (12) respective dans une position de limite extraite.

5. Lame selon l'une quelconque des revendications précédentes, caractérisée en ce que lesdits moyens élastiques (36) comprennent au moins un bloc (36) de matériau élastiquement déformable forcé entre un bord terminal de la partie de plaque allongée (12) respective et un corps de référence porté par ledit élément roulant (5).

6. Lame selon la revendication 5, caractérisée en ce que ledit bloc (36) de matériau élastiquement déformable est forcé entre une surface d'extrémité supérieure de ladite partie de plaque allongée (12) respective et une surface de butée dudit corps de référence.

7. Lame selon la revendication 5 ou 6, caractérisée en ce que lesdits moyens élastiques comprennent, pour chacune desdites parties de plaque allongées (12), une pluralité desdits blocs (36) de matériau élastiquement déformable répartis le long de la longueur de ladite partie de plaque allongée (12).

8. Lame selon la revendication 6 ou 7, caractérisée en ce que chacun desdits blocs (36) comprend au moins une partie tubulaire (39) ayant un axe (41) orthogonal à ladite partie de plaque allongée (12) respective.

9. Lame selon l'une quelconque des revendications précédentes, caractérisée en ce que chacun desdits ensembles de guidage et de coulissement (15) comprend deux plaques de guidage (22) (23) sensiblement plates, parallèles et se faisant face, logeant entre elles, d'une manière coulissante, un segment d'extrémité supérieur plat de ladite partie de plaque allongée (12) respective, une première (22) desdites plaques (22) (23) étant raccordée audit élément roulant (5).

10. Lame selon la revendication 9, caractérisée en ce que chacun desdits ensembles de guidage et de coulissement (15) comprend également une broche de référence (28, 31) respective portée par l'une desdites plaques et une fente (30) formée sur ladite partie de plaque (12) et mise en prise avec du jeu par ladite broche (28, 31).

11. Lame selon la revendication 9 ou 10, caractérisée en ce qu'elle comprend, en outre, un moyen d'articulation (16) intercalé entre ledit élément roulant (5) et ladite première plaque (22) pour permettre à ladite partie de plaque allongée (12) respective de tourner vers l'arrière par rapport à l'élément roulant (5) autour d'un axe de charnière (20) parallèle à ladite direction transversale indépendamment des autres parties de plaque allongées (12).

12. Lame selon la revendication 9 ou 10, caractérisée en ce que ladite première plaque (22) est raccordée de manière solidaire audit élément roulant (5).

13. Lame selon la revendication 9 ou 10, caractérisée en ce que lesdites premières plaques (22) sont portées par une structure de support commune (45) et en ce qu'elle comprend également un moyen de charnière (46) supplémentaire intercalé entre ledit élément roulant (5) et ladite structure de support commune (45) pour permettre auxdites parties de plaque allongées (12) de tourner simultanément par rapport à l'élément roulant (5) autour d'un axe de charnière (47) commun parallèle à ladite direction transversale ; des moyens élastiques (48) étant prévus pour maintenir ladite structure commune (45) dans une position de référence angulaire.

14. Lame selon l'une quelconque des revendications précédentes, caractérisée en ce que ledit couteau (8) comprend une pluralité desdites parties de plaque allongées (12) indépendantes l'une de l'autre.

Drawing