(19)
(11)EP 3 444 083 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
22.04.2020 Bulletin 2020/17

(21)Application number: 18275119.8

(22)Date of filing:  13.08.2018
(51)International Patent Classification (IPC): 
B26B 19/06(2006.01)
B26B 19/38(2006.01)
B26B 19/10(2006.01)

(54)

A SANDWICH-STRUCTURED CUTTER AND A HAIR TRIMMER

MESSER MIT SANDWICHSTRUKTUR UND HAARSCHNEIDER

DÉBROUSSAILLEUSE À STRUCTURE EN SANDWICH ET TONDEUSE À CHEVEUX


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 14.08.2017 CN 201710692966

(43)Date of publication of application:
20.02.2019 Bulletin 2019/08

(73)Proprietor: Specialife Industries Limited
New Territories (HK)

(72)Inventor:
  • LAU, Tung Yan
    New Territories (HK)

(74)Representative: Wilkinson, Stephen John 
Stevens Hewlett & Perkins 1 St Augustine's Place
Bristol BS1 4UD
Bristol BS1 4UD (GB)


(56)References cited: : 
EP-A1- 1 354 674
WO-A1-2005/053916
WO-A1-2015/158571
EP-A1- 2 926 959
WO-A1-2013/068893
  
      
    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

    Technical Field



    [0001] The present invention relates to the technical field of care supplies, and in particular relates to a sandwich-structured cutter and a hair trimmer using the cutter.

    Background Art



    [0002] Traditional hair scissors for personal care, for example, electric clippers and electrical shavers, generally consist of a cutter, a blade carrier and a handheld portion. The cutter generally comprises a fixed blade and a movable blade which overlap each other; a row of cutter teeth is provided at the front edge of the movable blade and the left and right sides of each cutter tooth are cutter edges; a row of cutter teeth is provided at the front edge of the fixed blade and each cutter tooth's inner surface contacting the movable blade and the side of the combing tooth form a sharp angle; the front edges of the movable blade and the fixed blade overlap each other, the movable blade is driven by the driving component in the blade carrier so that the movable blade moves horizontally relative to the fixed blade, and thus the hair in the clearance between combing teeth of the fixed blade is cut.

    [0003] However, since the movable blade, especially the cutter tooth at the front edge of the movable blade is exposed or partially exposed to the user, the user is apt to get injured or it may cause a mental burden to the user.

    Summary of the Invention



    [0004] To overcome the defects and disadvantages of the prior art, the objective of the present invention is to provide a cutter with an unexposed movable blade and a higher cutting efficiency, and a hair trimmer using the cutter.

    [0005] According to a solution of the present invention, a sandwich-structured cutter is provided and the cutter comprises:

    two fixed blades, each of which has a row of teeth at the front end, and

    a movable blade, which is sandwiched between the two fixed blades, can reciprocate relative to the two fixed blades in the longitudinal direction, and is an integrated blade,

    wherein the movable blade has a row of teeth at the front end, the front ends of the teeth of the movable blade do not protrude from the front ends of the teeth of the fixed blades, and each tooth of the movable blade has a quadrangular cross-section shape, which comprises parallel first pair sides and second pair sides forming four acute angles with the first pair sides.



    [0006] Preferably, each of second pair sides has at least one recess.

    [0007] Alternatively, at least one recess comprises an angled recess.

    [0008] Alternatively, at least one recess comprises an arced recess.

    [0009] Alternatively, the two sides of the second pair sides are symmetrical.

    [0010] Further, the cross-section shape of each tooth of the movable blade gradually becomes small from the root to the front end of the tooth and the length of the first pair sides remains unchanged.

    [0011] Alternatively, at least one surface of the movable blade has a plurality of recessed portions, or the movable blade has a plurality of perforated holes.

    [0012] Alternatively, an arced bulge is formed at the end, far away and/or near the movable blade, of each tooth of the two fixed blades.

    [0013] Preferably, the end of each tooth of the two fixed blades has a fillet.

    [0014] According to another solution of the present invention, a hair trimmer is provided and the hair trimmer comprises a driving rocker arm, a blade carrier, and the above-mentioned sandwich-structured cutter, wherein the two fixed blades are fixed on the blade carrier, and the driving rocker arm is pivotably fixed on the blade carrier and drives the movable blade to reciprocate.

    [0015] The advantageous effects of the present invention are:
    Through the design of the acute-angle cutting edge on the movable blade, the angle of the cutting edge is reduced and the cutting efficiency is improved. In addition, the design of the four acute-angle cutting edges enables the movable blade to cut not only the hair which is long enough to cross the two sides of the movable blade, but also the hair which is long enough to touch only one side of the movable blade. Moreover, hair of different lengths can be cut, no matter what direction the cutter is in.

    [0016] By preventing the front end of the movable blade from protruding from the front end of the fixed blade, the probability that the user gets injured can be reduced and the fear of using this type of cutter can be overcome.

    [0017] Through the integrated design of the movable blade in the present invention, instead of the combination of two or more separate components in the prior art, (i) any technical error in the depth of parallelism between the longitudinal plane of the movable blade and the longitudinal plane of each of the two fixed blades is reduced or eliminated, (ii) the procedural steps for manufacturing the blade are reduced and the molding cost is reduced so that the goal of reducing the manufacturing cost and manufacturing time is achieved.

    [0018] By enabling each of the second pair sides to have at least one recess and providing the variants such as angled- and/or arced recesses, as much hair as possible can enter the recess, waiting for cutting, when the user uses the hair trimmer. In addition, manufacturers can conveniently design the hair trimmer according to their own molds.

    [0019] By gradually reducing the cross-section shape of the teeth, the material for manufacturing teeth can be reduced, the overall weight of the cutter can be lightened, and as much hair as possible enters the teeth, waiting for cutting.

    [0020] Through the design of the recessed portions on the surface of the movable blade, the friction area between the movable blade and the fixed blades is reduced and thus the sliding friction force between them is reduced. In addition, a material such as lubricating oil/grease can be put into these recessed portions to further reduce the sliding friction force, thus prolonging the service life of the movable blade.

    [0021] Through the design of the arced bulge on at least one end of the two fixed blades and the design of the fillet at the end of a tooth, the user can be protected against any damage caused by blades during the operation of the cutter.

    Brief Description of the Drawings



    [0022] 

    Figure 1 shows the hair trimmer assembled with the sandwich-structured cutter in the present invention.

    Figure 2a shows the cross-section of the sandwich-structured cutter in the present invention.

    Figure 2b shows a tooth of the movable blade in the sandwich-structured cutter in the present invention.

    Figure 3 shows the movable blade of the cutter in a first implementation mode of the present invention.

    Figure 4 is an enlarged view of Part I of the movable blade shown in Figure 3.

    Figure 5 shows the movable blade of the cutter in a second implementation mode of the present invention.

    Figure 6 is an enlarged view of Part II of the movable blade shown in Figure 5.

    Figure 7 shows the two fixed blades of the cutter in a third implementation mode of the present invention.

    Figure 8 is a side view of Part III of the fixed blade shown in Figure 7.

    Figure 9 is an enlarged view of Part III of the fixed blade shown in Figure 7.

    Figure 10 shows the two fixed blades of the cutter in a fourth implementation mode of the present invention.

    Figure 11 is a side view of Part IV of the fixed blade F4 shown in Figure 10.

    Figure 12 is an enlarged view of Part IV of the fixed blade F4 shown in Figure 10.

    Figure 13 shows the two fixed blades of the cutter in a fourth implementation mode of the present invention.

    Figure 14 is a side view of Part V of the fixed blade shown in Figure 13.

    Figure 15 is an enlarged view of Part V of the fixed blade shown in Figure 13.

    Figure 16 is an exploded view of one implementation mode of the hair trimmer in the present invention.

    Figure 17 is a partially exploded view of the implementation mode of the hair trimmer shown in Figure 16.

    Figure 18 is a partially exploded view of the implementation mode of the hair trimmer shown in Figure 16.

    Figure 19 shows how the cutter in the present invention cuts hair.


    Detailed Description of the Invention



    [0023] According to the embodiments of the present invention, a sandwich-structured cutter is provided.

    [0024] Figure 1 shows the hair trimmer assembled with the sandwich-structured cutter in the present invention, and Figure 2a shows the cross-section of the sandwich-structured cutter in the present invention. As shown in Figure 1 and Figure 2a, the cutter comprises two fixed blades and one movable blade.

    [0025] Of the two fixed blades (first fixed blade and second fixed blade) FF and SF, each fixed blade has a row of teeth at the front end and the shape of the teeth of the fixed blades can be the same. After the two fixed blades are installed, the teeth of one fixed blade correspond to the teeth of the other fixed blade, that is to say, the clearances between teeth of one fixed blade correspond to the clearances between teeth of the other fixed blade. Or the teeth of the two fixed blade can be staggered, that is to say, the teeth of one fixed blade correspond to the clearances between the teeth of the other fixed blade.

    [0026] The movable blade M is sandwiched between the two fixed blades and can reciprocate relative to the two fixed blades FF and SF in the longitudinal direction of the movable blade M, and the movable blade M is an integrated blade.

    [0027] The movable blade M has a row of teeth at the front end, the front ends of the teeth of the movable blade M do not protrude from the front ends of the teeth of the fixed blades M, and each tooth of the movable blade M has a quadrangular cross-section shape, which comprises parallel first pair sides (FPS) and second pair sides (SPS) forming four acute angles with the first pair sides FPS.

    [0028] In the embodiments of the present invention, each of the second pair sides SPS can have at least one recess. At least one recess of the second pair sides can include, for example, an angled recess. In one embodiment, as shown in Figure 2b, the second pair sides of the quadrangular cross-section shape of the movable blade can comprise a blunt-angle recess. Or at least one recess of the second pair sides can include, for example, an arced recess. Figures 1 and 2 schematically show an arced recess which a second pair side SPS has. The shape of the second pair sides can include only an angled recess, or include only an arced recess, or include an angled recess and an arced recess, as long as the second pair sides SPS form four acute angles with the first pair sides FPS.

    [0029] In the embodiments of the present invention, the shapes of the two sides of the second pair sides can be symmetrical. Figures 1 and 2a schematically show two symmetrical arced recesses which the second pair sides SPS have.

    [0030] In some embodiments of the present invention, the cross-section shape of each tooth of the movable blade M can gradually become small from the root to the front end of the tooth and the length of the first pair sides remains unchanged.

    [0031] In another embodiment of the present invention, one surface of the body portion of the movable blade can have a plurality of recessed portions, which can be used to place lubricating oil on. The recessed portions on the surface of the movable blade can be in the shape of a cylinder or truncated cone. Alternatively, the two surfaces of the body portion of the movable blade can both have a plurality of recessed portions, and the shapes of the recessed portions on the two surfaces can be the same or different, and can be symmetrical or asymmetrical. Alternatively, the body portion of the movable blade can have a plurality of perforated holes which pass through the movable blade in the thickness direction. According to the embodiments of the present invention, the design of the surface of the movable blade can reduce the friction area between the movable blade and the fixed blades, and then can reduce the sliding friction force, and in addition, a material such as lubricating oil/grease can be put into these recessed portions to further reduce said sliding friction force.

    [0032] In some embodiments of the present inventions, an arced bulge is formed at the end, far away and/or near the movable blade, of each tooth of the two fixed blades, and the arced bulge can be integrated with the fixed blades or can be formed after the fixed blades are formed.

    [0033] In some embodiments of the present invention, the two ends of each tooth of the two fixed blades in the tooth arrangement direction can have a fillet.

    [0034] In some embodiments of the present invention, the teeth of the movable blade can be designed to be parallel. For example, they are all perpendicular to the front end of the body portion of the movable blade or form an angle of inclination. Alternatively, the teeth of movable blade can be designed to be non-parallel. For example, the bottoms of the two teeth in pair are close to or far away from each other, while the tops of the two teeth in pair are on the contrary far away or close to each other.

    [0035] The following will describe a plurality of implementation modes of the cutter according to the embodiment of the present invention.

    First implementation mode of the cutter



    [0036] Figure 3 shows the first implementation mode of the present invention and shows the movable blade M1 of the cutter in the first implementation mode of the present invention, and Figure 4 is an enlarged view of Part I of the movable blade shown in Figure 3.

    [0037] The movable blade M1 of the cutter in the first implementation mode of the present invention is an integrated blade and has a row of teeth at the front end, and each tooth has a quadrangular cross-section shape, which comprises parallel first pair sides FPS1 and second pair sides SPS1 forming four acute angles with the first pair sides FPS1. The first pair sides FPS1 contact the two fixed blades and form four acute-angle cutting edges (CEs), namely, first cutting edge CE1, second cutting edge CE2, third cutting edge CE3, and fourth cutting edge CE4, with the two fixed blades on the cross-section. Wherein each of the second pair sides SPS2 has an arced recess and the two sides of the second pair sides SPS2 are symmetrical. In the present implementation mode, the movable blade has a plurality of perforated holes PH1, which can be used to place lubricating oil on.

    Second implementation mode of the cutter



    [0038] Figure 5 shows the second implementation mode of the present invention and shows the movable blade M2 of the cutter in the second implementation mode of the present invention, and Figure 6 is an enlarged view of Part II of the movable blade shown in Figure 5.

    [0039] The movable blade M2 of the cutter in the second implementation mode of the present invention is an integrated blade and has a row of teeth at the front end, and each tooth has a quadrangular cross-section shape, which comprises parallel first pair sides FPS2 and second pair sides SPS2 forming four acute angles with the first pair sides FPS2. The first pair sides FPS2 contact the two fixed blades and form four acute-angle cutting edges with the two fixed blades on the cross section. Each side of the second pair sides SPS2 has a plurality of arced recesses similar to waveforms. Figures 5 and 6 schematically show limited numbers of peaks and troughs of a plurality of arced recesses. In practice, the numbers and arrangement mode of peaks and troughs can be determined by the manufacturer. In addition, the two sides of the second pair sides SPS2 are symmetrical. In the present implementation mode, the movable blade has a plurality of perforated holes PH2, which can be used to place lubricating oil on.

    Third implementation mode of the cutter



    [0040] Figure 7 shows the third implementation mode of the present invention and shows the two fixed blades F3 of the cutter in the third implementation mode of the present invention, Figure 8 is a side view of part III of the fixed blades F3 shown in Figure 7, and Figure 9 is an enlarged view of part III of the fixed blades F3 shown in Figure 7.

    [0041] Each of the two fixed blades, namely, the first fixed blade FF3 and the second fixed blade SF3, of the cutter in the third implementation mode of the present invention has a row of teeth at the front end. Wherein, after the two fixed blades are assembled into a cutter, a clearance is reserved between them and the movable blade can be sandwiched in the clearance. The inner surface of the first fixed blade FF3 and the inner surface of the second fixed blade SF3 contact the movable blade to cut hair. Each tooth has a fillet on the two sides of the front end to prevent scratching the skin of the user. As shown in Figure 9, the cross-sections of the teeth of the two fixed blades are isosceles trapezoids, that is to say, a sharp angle is formed between the tooth edges where the two fixed blades contact the movable blade so as to improve the cutting efficiency.

    Fourth implementation mode of the cutter



    [0042] Figure 10 shows the fourth implementation mode of the present invention and shows the two fixed blades F4 of the cutter in the fourth implementation mode of the present invention, Figure 11 is a side view of part IV of the fixed blades F4 shown in Figure 10, and Figure 12 is an enlarged view of part IV of the fixed blades F4 shown in Figure 10.

    [0043] Each of the two fixed blades, namely, the first fixed blade FF4 and the second fixed blade SF4, of the cutter in the fourth implementation mode of the present invention has a row of teeth at the front end. Wherein, after the two fixed blades are assembled into a cutter, a clearance is reserved between them and the movable blade can be sandwiched in the clearance. The inner surface of the first fixed blade FF4 and the inner surface of the second fixed blade SF4 contact the movable blade to cut hair. Each tooth has a fillet on the two sides of the front end. An arced bulge is formed at the end, far away from the movable blade to be assembled, of each tooth of the two fixed blades to protect the user against any injury caused by the blades during the operation of the cutter. In addition, the connected portion between the arced bulge and the teeth has also undergone fillet treatment, and therefore it will not injure the user.

    Fifth implementation mode of the cutter



    [0044] Figure 13 shows the fifth implementation mode of the present invention and shows the two fixed blades F5 of the cutter in the fifth implementation mode of the present invention, Figure 14 is a side view of part V of the fixed blades F5 shown in Figure 13, and Figure 15 is an enlarged view of part V of the fixed blades F5 shown in Figure 13.

    [0045] The cutter in the fifth embodiment mode of the present invention comprises two fixed blades, namely, a first fixed blade FF5 and a second fixed blade SF5. The difference of the fifth implementation mode from the fourth implementation mode is that an arced bulge is formed at the end, near the movable blade to be assembled, of each tooth of the two fixed blades and the bulge can also protect the user against any injury caused by the blades during the operation of the blades. In addition, the connected portion between the arced bulge and the teeth has also undergone fillet treatment, and therefore it will not injure the user.

    [0046] According to another embodiment of the present invention, a hair trimmer is provided and the hair trimmer comprises a driving rocker arm, a blade carrier, and the above-mentioned sandwich-structured cutter, wherein the two fixed blades are fixed on the blade carrier, and the driving rocker arm is pivotably fixed on the blade carrier and drives the movable blade to reciprocate to realize cutting.

    [0047] Figure 16 is an exploded view of one implementation mode of the hair trimmer in the present invention. According to the present invention, the hair trimmer can comprise a pressure frame 1, a pressure spring 2, an axle sleeve 3, a rocker arm 4 (namely, driving rocker arm), a blade carrier cover 5, a blade carrier 6, and a sandwich-structured cutter consisting of two fixed blades FF and SF and a movable blade M.

    [0048] Figure 17 is a partially exploded view of the implementation mode of the hair trimmer shown in Figure 16. In Figure 17, the pressure frame 1, the pressure spring 2, and the blade carrier cover 5 are not assembled on the hair trimmer.

    [0049] Figure 18 is a partially exploded view of the implementation mode of the hair trimmer shown in Figure 16. In Figure 18, one fixed blade FF is not assembled on the hair trimmer.

    [0050] Figure 19 shows how the cutter in the present invention cuts hair. Figure 19i shows the cross-section of the cutter and there is no hair in the cutter, Figure 19ii shows a hair in the clearance between three blades, and Figure 19iii shows that the movable blade can be driven by the driving rocker arm to move upward to cut the hair.

    [0051] In the present invention, the above-mentioned implementation modes can be combined, without departing from the scope of the present invention.


    Claims

    1. Sandwich-structured cutter, characterized in that it comprises:

    two fixed blades (FF, SF), each of which has a row of teeth at the front end, and

    a movable blade (M), which is sandwiched between said two fixed blades (FF, SF), can reciprocate relative to said two fixed blades (FF, SF) in the longitudinal direction, and is an integrated blade,

    wherein said movable blade (M) has a row of teeth at the front end, the front ends of the teeth of the movable blade (M) do not protrude from the front ends of the teeth of said fixed blades (FF, SF), and each tooth of said movable blade (M) has a quadrangular cross-section shape, which comprises parallel first pair sides (FPS) and second pair sides (SPS) forming four acute angles with said first pair sides (FPS).


     
    2. Cutter according to claim 1, characterized in that each of said second pair sides (SPS) has at least one recess.
     
    3. Cutter according to claim 2, characterized in that said at least one recess comprises an angled recess.
     
    4. Cutter according to claim 2, characterized in that said at least one recess comprises an arced recess.
     
    5. Cutter according to claim 1, characterized in that the two sides of said second pair sides (SPS) are symmetrical.
     
    6. Cutter according to claim 1, characterized in that the cross-section shape of each tooth of said movable blade (M) gradually becomes small from the root to the front end of the tooth and the length of said first pair sides (FPS) remains unchanged.
     
    7. Cutter according to any of claims 1 to 5, characterized in that at least one surface of said movable blade (M) has a plurality of recessed portions, or said movable blade (M) has a plurality of perforated holes (PH1).
     
    8. Cutter according to any of claims 1 to 5, characterized in that an arced bulge is formed at the end, far away and/or near the movable blade (M), of each tooth of said two fixed blades (FF, SF).
     
    9. Cutter according to any of claims 1 to 5, characterized in that the end of each tooth of said two fixed blades (FF, SF) has a fillet.
     
    10. Hair trimmer, characterized in that it comprises a driving rocker arm (4), a blade carrier (6), and the sandwich-structured cutter as claimed in any of claims 1 to 9, wherein said two fixed blades (FF, SF) are fixed on said blade carrier (6), and said driving rocker arm (4) is pivotably fixed on said blade carrier (6) and drives said movable blade (M) to reciprocate.
     


    Ansprüche

    1. Schneideeinrichtung mit Sandwichaufbau, dadurch gekennzeichnet, dass sie umfasst:

    zwei unbewegliche Messer (FF, SF), die jeweils eine Reihe von Zähnen am vorderen Ende aufweisen, und

    ein bewegliches Messer (M), das sandwichartig zwischen die beiden unbeweglichen Messer (FF, SF) eingefügt ist, sich in Bezug auf die beiden unbeweglichen Messer (FF, SF) in der Längsrichtung hin- und herbewegen kann und ein integriertes Messer ist,

    wobei das bewegliche Messer (M) eine Reihe von Zähnen am vorderen Ende aufweist, die vorderen Enden der Zähne des beweglichen Messers (M) von den vorderen Enden der Zähne der unbeweglichen Messer (FF, SF) nicht vorstehen, und jeder Zahn des beweglichen Messers (M) eine viereckige Querschnittsform aufweist, die ein erstes Paar paralleler Seiten (FPS) und ein zweites Paar paralleler Seiten (SPS) umfasst, das vier spitze Winkel mit dem ersten Paar Seiten (FPS) bildet.


     
    2. Schneideeinrichtung nach Anspruch 1, dadurch gekennzeichnet, dass jede Seite des zweiten Paares (SPS) mindestens eine Aussparung aufweist.
     
    3. Schneideeinrichtung nach Anspruch 2, dadurch gekennzeichnet, dass die mindestens eine Aussparung eine abgewinkelte Aussparung umfasst.
     
    4. Schneideeinrichtung nach Anspruch 2, dadurch gekennzeichnet, dass die mindestens eine Aussparung eine gewölbte Aussparung umfasst.
     
    5. Schneideeinrichtung nach Anspruch 1, dadurch gekennzeichnet, dass die beiden Seiten des zweiten Paares Seiten (SPS) symmetrisch sind.
     
    6. Schneideeinrichtung nach Anspruch 1, dadurch gekennzeichnet, dass die Querschnittsform jedes Zahns des beweglichen Messers (M) von der Wurzel zum vorderen Ende des Zahns schrittweise kleiner wird, und die Länge des ersten Paares Seiten (FPS) unverändert bleibt.
     
    7. Schneideeinrichtung nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, dass mindestens eine Fläche des beweglichen Messers (M) eine Mehrzahl von ausgesparten Abschnitten aufweist, oder das bewegliche Messer (M) eine Mehrzahl von perforierten Löchern (PH1) aufweist.
     
    8. Schneideeinrichtung nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, dass eine gewölbte Ausbauchung am Ende jedes Zahns der beiden unbeweglichen Messer (FF, SF) weit entfernt vom beweglichen Messer (M) und/oder in der Nähe davon ausgebildet ist.
     
    9. Schneideeinrichtung nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, dass das Ende jedes Zahns der beiden unbeweglichen Messer (FF, SF) eine Abrundung aufweist.
     
    10. Haarschneidegerät, dadurch gekennzeichnet, dass es eine Antriebsschwinge (4), einen Messerträger (6) und die Schneideeinrichtung mit Sandwichaufbau nach einem der Ansprüche 1 bis 9 umfasst, wobei die beiden unbeweglichen Messer (FF, SF) auf dem Messerträger (6) befestigt sind, und die Antriebsschwinge (4) drehbar auf dem Messerträger (6) befestigt ist und das bewegliche Messer (M) zur Hin- und Herbewegung antreibt.
     


    Revendications

    1. Débroussailleuse à structure en sandwich, caractérisée en ce qu'elle comprend :

    deux lames fixes (FF, SF), chacune comportant une rangée de dents au niveau de l'extrémité avant, et

    une lame mobile (M) qui est prise en sandwich entre lesdites deux lames fixes (FF, SF), peut avoir un mouvement de va-et-vient par rapport auxdites deux lames fixes (FF, SF) dans la direction longitudinale, et est une lame intégrée,

    dans laquelle ladite lame mobile (M) comporte une rangée de dents au niveau de l'extrémité avant, les extrémités avant des dents de la lame mobile (M) ne font pas saillie des extrémités avant des dents desdites deux lames fixes (FF, SF), et chaque dent de ladite lame mobile (M) présente une forme de section transversale quadrangulaire, qui comprend une première paire de côtés (FPS) et une seconde paire de côtés (SPS) parallèles formant quatre angles aigus avec ladite première paire de côtés (FPS).


     
    2. Débroussailleuse selon la revendication 1, caractérisée en ce que chacun de ladite seconde paire de côtés (SPS) comporte au moins un évidement.
     
    3. Débroussailleuse selon la revendication 2, caractérisée en ce que ledit évidement comprend un évidement oblique.
     
    4. Débroussailleuse selon la revendication 2, caractérisée en ce que ledit évidement comprend un évidement arqué.
     
    5. Débroussailleuse selon la revendication 1, caractérisée en ce que les deux côtés de ladite seconde paire de côtés (SPS) sont symétriques.
     
    6. Débroussailleuse selon la revendication 1, caractérisée en ce que la forme de section transversale de chaque dent de ladite lame mobile (M) se réduit progressivement du pied à l'extrémité avant de la dent, et la longueur de ladite première paire de côtés (FPS) reste la même.
     
    7. Débroussailleuse selon l'une quelconque des revendications 1 à 5, caractérisée en ce qu'au moins une surface de ladite lame mobile (M) présente une pluralité de parties évidées, ou ladite lame mobile (M) comporte une pluralité de trous perforés (PH1).
     
    8. Débroussailleuse selon l'une quelconque des revendications 1 à 5, caractérisée en ce qu'un bombement arqué est formé au niveau de l'extrémité, éloignée et/ou proche de la lame mobile (M), de chaque dent desdites deux lames fixes (FF, SF).
     
    9. Débroussailleuse selon l'une quelconque des revendications 1 à 5, caractérisée en ce que l'extrémité de chaque dent desdites deux lames fixes (FF, SF) présente une moulure.
     
    10. Tondeuse à cheveux, caractérisée en ce qu'elle comprend un bras oscillant d'entraînement (4), un porte-lame (6) et la débroussailleuse à structure en sandwich selon l'une quelconque des revendications 1 à 9, dans laquelle lesdites deux lames fixes (FF, SF) sont fixées sur ledit porte-lame (6), et ledit bras oscillant d'entraînement (4) est fixé en pivot sur ledit porte-lame (6) et entraîne ladite lame mobile (M) en un mouvement de va-et-vient.
     




    Drawing