(19)
(11)EP 1 365 195 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
10.09.2008 Bulletin 2008/37

(21)Application number: 03010948.2

(22)Date of filing:  16.05.2003
(51)Int. Cl.: 
F23Q 2/16  (2006.01)

(54)

Lighter safety mechanism

Feuerzeug mit Sicherheitsvorrichtung

Briquet à mécanisme de sécurité


(84)Designated Contracting States:
DE ES FR GB IT

(30)Priority: 21.05.2002 US 153843

(43)Date of publication of application:
26.11.2003 Bulletin 2003/48

(73)Proprietor: Huang, Xin Hua
Cixi City, Ningbo (CN)

(72)Inventor:
  • Kim, Jin Ki c/o Bultina America Corporation
    Fullerton, CA 92833 (US)

(74)Representative: Vetter, Ewald Otto et al
Meissner, Bolte & Partner Anwaltssozietät GbR (Depotstrasse 5 1/2, 86199 Augsburg), Postfach 10 26 05
86016 Augsburg
86016 Augsburg (DE)


(56)References cited: : 
US-A- 5 829 963
US-B1- 6 217 313
  
      
    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 a safety mechanism for a lighter according to the preamble of claim 1. Such a safety mechanism is known from US-A-5 829 963. A lock member positioned between a cap and an ignition pushbutton includes a rigid leg. The rigid leg sits on the space between the top end of the casing and the plunger to prevent the trigger from coming down any further. A finger pressure of a user must be used to shift the end of the rigid leg 16 into the space adjacent to the piezoelectric unit 8.
    US-A-6 217 313 discloses a childproof barbeque iighter that includes a locker device 6 and a pusher button 50 which are movable together in vertical direction such that when the locker device is locked up then the pusher button 50 is locked and cannot be pushed downward to compress the piezoelectric unit 40. A locking arm 61 has a predetermined length and extends downwardly so that it reaches a top edge of the side wall 43 of the piezoelectric unit 40. Thus, the side wall 43 substantially blocks up any downward movement of the locker device 6 as well as the pusher button 50.

    [0002] Some types of lighters typically include a piezoelectric unit, which when operated, produces sparks to ignite a stream of flammable gas. A conventional piezoelectric unit includes a plunger which is moveable within a main casting. The main casting includes an electrical ceramic element. When the plunger is pressed into the main casting, its bottom portion strikes the electrical ceramic element to generate an electric current. In a typical lighter, flammable gas is supplied from a chamber to a nozzle. The electric current produced by the piezoelectric unit is delivered to a position near the nozzle where it is emitted as a spark to ignite the gas that is streaming out of the nozzle.

    [0003] The use of conventional lighters is relatively simple. In conventional lighters, for example, the plunger of the piezoelectric unit is connected to a trigger, a button, or some other actuating mechanism that can be manipulated by a user to press the plunger into the main casting of the piezoelectric unit. The simplicity of operation of conventional lighters is disadvantageous as it makes it easy for children to ignite the lighter thereby creating a risk of accidental fires. To reduce the risk of misuse by children, mechanisms have been incorporated in lighters to make their use more complicated. Often such mechanisms include a safety feature which must first be actuated before the lighter is ready to be used. A well known mechanism for preventing usage of a lighter by children involves a mechanism for obstructing the motion of the trigger to prevent ignition of the lighter. U.S. Pat. No. 6,135,762, for example, shows a lighter which includes a feature that engages the trigger to obstruct its motion. Such mechanisms work well. Generally, however, such safety mechanisms include a trigger mechanism having unique features. Thus, to take advantage of such safety mechanisms, the trigger mechanism of the lighter must be designed according to such unique features. That means that each commercial lighter must be customized to include the unique features. It is desirable to provide a safety mechanism that can be universally incorporated into all commercial lighters utilizing a piezoelectric unit, without regard to the configuration of the trigger itself.

    SUMMARY OF THE INVENTION



    [0004] It is an object of the present invention to provide a lighter safety mechanism that might be incorporated in any lighter which includes a piezoelectric ignition unit.

    [0005] A lighter regardless of the purpose for which the lighter may be used and regardless of its shape and size, according to the present invention includes a universal safety mechanism for a piezoelectric lighter ignition unit. That mechanism has an ignition plunger that is selectively moveable within a main casting to generate a spark for igniting a stream of flammable gas, and some type of locking object or stop obstructs the movement of the plunger into the main casting to prevent ignition.

    [0006] The plunger of the piezoelectric unit according to the present invention includes a notch on one side thereof. The notch has an open surface which is oriented transverse to the direction of motion of the plunger. The latch includes a stop portion which is selectively moveable to a position where it may oppose the transverse open surface in order to obstruct the motion of the plunger.

    [0007] In a lighter safety mechanism according to the preferred embodiment, the latch includes an arm which is integral with the stop portion to form a unitary L-shaped latch. The arm portion extends from the interior of the housing of the lighter that houses the piezoelectric unit to the exterior of the housing where it may be manipulated by a user to selectively move the stop portion from a stop position where it opposes the transverse open surface to an open position away from the transverse open surface to allow the plunger to be pressed freely into the main casting. According to the preferred embodiment, the latch is spring-loaded so that it is returned to a position where its stop portion may oppose the transverse open surface when the user stops manipulating the arm. Alternative types of stops or obstacle elements share in common the movability between the stop and open plunger motion positions.

    [0008] Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.

    BRIEF DESCRIPTION OF THE DRAWINGS



    [0009] Fig. 1A shows a side elevation view of a piezoelectric unit according to an embodiment of the present invention;

    [0010] Fig. 1B shows a partially exploded perspective view of a lighter safety mechanism according to the present invention which includes the piezoelectric unit of Fig. 1A, and a latch that engages the plunger of the piezoelectric unit to prevent the piezoelectric unit from operating;

    [0011] Fig. 1C shows a perspective view in which the latch shown in Fig. 1B engages the plunger of the piezoelectric unit to prevent the piezoelectric unit from operating;

    [0012] Fig. 1D shows a perspective view in which the latch shown in Fig. 1C has disengaged from the plunger of the piezoelectric unit to allow the piezoelectric unit to operate;

    [0013] Fig. 2A shows schematically a side view of the interior of a lighter having a lighter safety mechanism that is engaged according to the present invention;

    [0014] Fig. 2B is a cross-sectional view of the lighter shown in Fig. 2B along line 2B-2B in Fig. 2A looking in the direction of the arrows;

    [0015] Fig. 2C shows schematically a side view of the interior of a lighter having a lighter safety mechanism according to the present invention in a disengaged condition;

    [0016] Fig. 2D is a cross-sectional view of the lighter shown in Fig. 2C along line 2D-2D in Fig. 2C looking in the direction of the arrows.

    DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT



    [0017] Fig. 1A shows a side view of a piezoelectric lighter ignition unit 10 that is used in a lighter according to the present invention. Piezoelectric unit 10 includes a main casting 12 and a plunger 14. Main casting 12 includes an opening which receives an end of plunger 14 and allows the same to be selectively moved inside main casting 12. As is conventionally known, piezoelectric unit 10 generates electricity and transmits the same to wire 16 when plunger 14 is pressed and thus caused to move inside main casting 12. The generated electricity is used to produce a spark to light a stream of flammable gas. Unless urged by an external force, most of the body of plunger 14 extends outside of main casting 12. Plunger 14 is spring loaded, however, by a spring inside casting 12 so that when the external force that urges plunger 14 into the main casting 12 ceases, plunger 14 returns to its original extended position.

    [0018] Referring now to Figs. 1A-1D, plunger 14 includes a notch 18 on a side thereof. Notch 18 includes open surface 18a which is transverse to the direction of movement of plunger 14 into main casting 12. Notch 18 is large enough to receive stop portion 20 of latch 22. Referring specifically to Fig. 1C, once stop portion 20 of latch 22 is received in notch 18, transverse open surface 18a is opposed by stop portion 20 when plunger 14 is pressed in an inward direction into main casting 12. The contact between transverse open surface 18a and stop portion 20 obstructs the movement of plunger 14, thereby preventing the production of a spark that lights the flammable gas. As shown in Fig. 1D, once stop portion 20 is moved away from transverse open surface 18a, plunger 14 is free to move inwardly into main casting 12 to produce a spark to light the flammable gas.

    [0019] Piezoelectric unit 10 as incorporated in a lighter is shown in Figs. 2A-2D. Referring to Fig. 2A, piezoelectric unit 10 is disposed in the interior of a housing 11. The free end of plunger 14 extends into a trigger 24. Trigger 24 is attached to the free end of plunger 14 to allow a user to press plunger 14 inwardly into main casting 12. Trigger 24 includes fuel release member 26 which extends in the direction of movement of plunger 14. As trigger 24 is pressed to press plunger 14 inwardly into casting 12 to produce a spark, the free end of member 26 contacts lever 28. This contact causes lever 28 to be moved in the direction of plunger 14. The movement of lever 28 causes a valve (not shown) to be opened to allow flammable gas to enter fuel tube 30 through nozzle 32 from fuel chamber 34. As plunger 14 is further pressed into main casting 12, a spark is produced to light the flammable gas.

    [0020] Referring now to Fig. 2B, latch 22 includes arm 36 which is integral with stop portion 20 and extends from the interior of housing 11 to its exterior. Arm 36 is slidably received by first 38 and second 40 snap-in latch supports. First 38 and second 40 snap-in latch supports are spaced from one another along arm 36 and are attached to an interior wall of housing 11. Stopper 42 is attached to arm 36. Compression spring 44 on arm 36 is disposed between stopper 42 and second snap-in latch support 40. Arm 36 also has knob 46 disposed at its free end to make it more comfortable for the user to press the end of arm 36.

    [0021] Now referring to Figs. 2B and 2D, in its natural, expanded state, spring 44 presses against second snap-in latch support 40 and stopper 42, thereby keeping the two spaced at a predetermined distance set by abutment of stopper 42 with the interior housing 11. As a result, stop portion 20 is moved into notch 18 where transverse open surface 18a (Fig. 1A) is opposed by stop portion 20 to prevent the inward movement of plunger 14 into the interior of main casting 12. To release plunger 14, a user applies force to knob 46 at the end of arm 36. This force moves stop portion 20 out of the path of transverse open surface 18a (Fig. 1A) allowing plunger 14 to be pressed inwardly into main casting 12. Also, this force causes stopper 42 to be moved toward second snap-in latch support 40 causing spring 44 to be squeezed therebetween. When the force is removed from knob 46, spring 44 returns to its natural, extended state, thus forcing second snap-in latch support 40 and stopper 42 to be spaced apart. While second snap-in latch support 40 and stopper 42 are being spaced apart by the expansion of spring 44, plunger 14 is allowed to move outwardly outside of the interior of main casting 12 thus allowing stop portion 20 to be received in notch 18 (Fig. 1A) and to oppose transverse open surface 18A (Fig. 1A). Hence, the lighter according to the present invention cannot be operated unless plunger 14 is released by application of force to knob 46 at the end of arm 36. It is noteworthy that a lighter safety mechanism according to the present invention can be universally incorporated in any purpose lighter in that its operation does not depend on the configuration of the trigger or any other part of the lighter.

    [0022] Although the present invention has been described in relation to a particular embodiment thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. Therefore, the present invention is limited not by the specific disclosure herein, but only by the appended claims.


    Claims

    1. A safety mechanism for selective prevention of the operation of a piezoelectric unit for a lighter comprising:

    a main casting (12);

    a piezoelectric lighter ignition unit (10) having a plunger (14) that is selectively moveable into said main casting (12) to generate a spark for ignition of a flammable gas,

    a movable stop portion (20) of a latch (22) movable between a plunger stopping position and an open, plunger moving position, the stop (20) being shaped and positioned for preventing the plunger (14) from moving into the main casting (12) when the stop (20) is in the stopping position and permitting the plunger (14) moving into the main casting (12) with the stop (20) in the open position,

    characterized in that

    the plunger (14) comprises a notch (18) on a side thereof oriented transversely to a direction of motion of said plunger (14) into said main casting (12), said movable stop (20) being positioned adjacent to the plunger (14) and being received in the notch (18) of the plunger (14) at the plunger stopping position and being disengaged from the notch (18) of the plunger (14) at the plunger moving position.


     
    2. The safety mechanism according to claim 1, wherein said lacht (22) includes an arm (36) that extends out of said main casting (12) such that said latch (22) is operable to its positions by motion of the latch along the length of the arm (36).
     
    3. The safety mechanism according to claim 2, further comprising a knob (46) disposed on an end of said arm (36) for moving said arm (36).
     
    4. The safety mechanism according to claim 2 or 3, further comprising a latch support (38, 40) disposed in said main casting (12) and slidably receiving said arm (36) as it moves.
     
    5. The safety mechanism according to at least one of claims 2 to 4, wherein said stop (20) of said latch (22) forms an L shaped unitary latch together with said arm (36).
     
    6. The safety mechanism according to at least one of claims 2 to 5, wherein said stop (20) and said arm (36) are integrally connected.
     
    7. The safety mechanism according to at least one of the preceding claims, further comprising an operable trigger (24) operatively connected to said plunger (14) for moving said plunger into said main casting (12).
     
    8. The safety mechanism according to at least one of the preceding claims, further comprising a chamber (34) for housing flammable fluid lighter fuel, a valve (26) openable to allow fuel to exit said chamber (34).
     
    9. The safety mechanism according to claim 8, further comprising a lever (28) operable for opening said valve (26), and the trigger (24) including a portion that abuts said lever (28) and operates said lever for opening said valve (26) when said trigger (24) is operated to move said plunger (14) into said main casting (12).
     
    10. The safety mechanism of at least one of claims 2 to 9, said arm (36) extending from inside to outside of said main casting (12).
     
    11. In combination:

    a lighter comprising a housing (11); and

    a safety mechanism according to one of the preceding claims in the housing.


     
    12. The combination of claim 11, further comprising a spring (44) normally urging the stop (20) to the plunger stopping position.
     
    13. The combination of claim 12, further comprising a stop in said housing (11), a stopper (42) disposed on and moveable with said arm (36), and the spring (44) disposed between said stopper (42) and said latch support (38, 40) and said spring (44) normally urging said stopper (42) to engage said stop in said housing (11); said stopper (42) is so placed on said arm (36) that with said stopper (42) engaging said stop, said arm (36) operates said latch (22) to said stopping position, and said arm (36) is movable to move said stop (20) of said latch (23) to said open position.
     


    Ansprüche

    1. Sicherheitsmechanismus zur selektiven Verhinderung der Betätigung einer piezoelektrischen Einheit für ein Feuerzeug, aufweisend:

    ein Hauptgussteil (12);

    eine piezoelektrische Feuerzeug-Zündeinheit (10) mit einem Stößel (14), welcher selektiv in das Hauptgussteil (12) bewegbar ist, um einen Funken zur Zündung eines entzündbaren Gases zu erzeugen,

    einen beweglichen Anschlagsteil (20) einer Verriegelung (22), welcher zwischen einer Stößelanschlagsposition und einer offenen Stößelbewegungsposition bewegbar-ist, wobei der Anschlag (20) so geformt und positioniert ist, dass er den Stößel (14) daran hindert, sich in das Hauptgussteil (12) hineinzubewegen, wenn der Anschlag (20) sich in der Anschlagsposition befindet, und es dem Stößel (14) erlaubt, sich in das Hauptgussteil (12) hineinzubewegen, wenn der Anschlag (20) sich in der offenen Position befindet,

    dadurch gekennzeichnet,

    dass der Stößel (14) an einer seiner Seiten eine Einkerbung (18) aufweist, welche quer zu einer Bewegungsrichtung des Stößels (14) in das Hauptgussteil (12) ausgerichtet ist, wobei der bewegliche Anschlag (20) zum Stößel (14) benachbart positioniert ist und in der Einkerbung (18) des Stößels (14) in der Stößelanschlagsposition aufgenommen wird und mit der Einkerbung (18) des Stößels (14) in der Stößelbewegungsposition nicht im Eingriff ist.


     
    2. Sicherheitsmechanismus nach Anspruch 1, wobei die Verriegelung (22) einen Arm (36) aufweist, der sich aus dem Hauptgussteil (12) so herauserstreckt, dass die Verriegelung (22) durch Bewegung der Verriegelung längs der Länge des Arms (36) in ihre Positionen verfahrbar ist.
     
    3. Sicherheitsmechanismus nach Anspruch 2, ferner aufweisend einen Knopf (46), der an einem Ende des Arms (36) zur Bewegung des Arms (36) angeordnet ist.
     
    4. Sicherheitsmechanismus nach Anspruch 2 oder 3, ferner aufweisend einen Verriegelungshalter (38, 40), welcher in dem Hauptgussteil (12) angeordnet ist und den Arm gleitbar aufnimmt, wenn er sich bewegt.
     
    5. Sicherheitsmechanismus nach mindestens einem der Ansprüche 2 bis 4, wobei der Anschlag (20) der Verriegelung (22) zusammen mit dem Arm (36) eine L-förmige einheitliche Verriegelung bildet.
     
    6. Sicherheitsmechanismus nach mindestens einem der Ansprüche 2 bis 5, wobei der Anschlag (20) und der Arm (36) integral verbunden sind.
     
    7. Sicherheitsmechanismus nach mindestens einem der vorhergehenden Ansprüche, ferner aufweisend einen betätigbaren Auslöser (24), der funktionsmäßig mit dem Stößel (14) verbunden ist, um den Stößel in das Hauptgussteil (12) zu bewegen.
     
    8. Sicherheitsmechanismus nach mindestens einem der vorhergehenden Ansprüche, ferner aufweisend eine Kammer (34) zur Unterbringung eines brennbaren Fluidfeuerzeugbrennstoffes, ein Ventil (26), welches zu öffnen ist, um es dem Brennstoff zu ermöglichen, die Kammer (34) zu verlassen.
     
    9. Sicherheitsmechanismus nach Anspruch 8, ferner aufweisend einen Hebel (28), welcher zum Öffnen des Ventils (26) betätigbar ist und der Auslöser (24) einen Teil aufweist, der an den Hebel (28) anschlägt und den Hebel zum Öffnen des Ventils (26) betätigt, wenn der Auslöser (24) betätigt wird, um den Stößel (14) in das Hauptgussteil (12) hineinzubewegen.
     
    10. Sicherheitsmechanismus nach mindestens einem der Ansprüche 2 bis 9, wobei der Arm (36) sich vom Innern des Hauptgussteils (12) zu seiner Außenseite erstreckt.
     
    11. In Kombination:

    ein Feuerzeug, aufweisend ein Gehäuse (11); und

    ein Sicherheitsmechanismus nach einem der vorhergehenden Ansprüche in dem Gehäuse.


     
    12. Kombination nach Anspruch 11, ferner aufweisend eine Feder (44), welche den Anschlag (20) normalerweise in die Stößelanschlagsposition drängt.
     
    13. Kombination nach Anspruch 12, ferner aufweisend einen Anschlag in dem Gehäuse (11), ein Anschlagselement (42), das an dem Arm (36) angeordnet ist und mit ihm bewegbar ist, und wobei die Feder (44) zwischen dem Anschlagselement (42) und dem Verriegelungshalter (38, 40) angeordnet ist und die Feder (44) das Anschlagselement (42) normalerweise dazu drängt, mit dem Anschlag in dem Gehäuse (11) in Eingriff zu gelangen; wobei das Anschlagselement (42) so an dem Arm (36) angeordnet ist, dass der Arm (36) die Verriegelung (22) in die Anschlagsposition bewegt, wenn das Anschlagselement (42) mit dem Anschlag in Eingriff ist, wobei der Arm bewegbar ist, um den Anschlag (20) der Verriegelung (23) in die offene Position zu bewegen.
     


    Revendications

    1. Mécanisme de sécurité destiné à empêcher sélectivement l'utilisation d'une unité piézoélectrique pour briquet, comportant :

    une pièce moulée principale (12) ;

    une unité piézoélectrique (10) d'allumage du briquet dotée d'un plongeur (14) qui peut être déplacé sélectivement pour l'introduire dans ladite pièce moulée principale (12) afin de générer une étincelle en vue de l'allumage d'un gaz inflammable,

    une partie (20) de butée mobile d'un loquet (22) susceptible d'être déplacée entre une position d'arrêt du plongeur et une position ouverte de mouvement du plongeur, la butée (20) étant conformée et positionnée de façon à empêcher le plongeur (14) d'entrer dans la pièce moulée principale (12) lorsque la butée (20) se trouve en position d'arrêt et à permettre au plongeur (14) d'entrer dans la pièce moulée principale (12) lorsque la butée (20) se trouve en position ouverte,

    caractérisé en ce que

    le plongeur (14) comporte sur un de ses côtés une encoche (18) orientée transversalement par rapport à une direction d'entrée dudit plongeur (14) dans ladite pièce moulée principale (12), ladite butée mobile (20) étant positionnée au voisinage dudit plongeur (14) et étant logée dans l'encoche (18) du plongeur (14) dans la position d'arrêt du plongeur et étant dégagée de l'encoche (18) du plongeur (14) dans la position de mouvement du plongeur.


     
    2. Mécanisme de sécurité selon la revendication 1, ledit loquet (22) comprenant un bras (36) qui s'étend hors de ladite pièce moulée principale (12) de telle sorte que ledit loquet (22) puisse être actionné vers ses positions par un mouvement du loquet sur la longueur du bras (36).
     
    3. Mécanisme de sécurité selon la revendication 2, comportant en outre un bouton (46) disposé sur une extrémité dudit bras (36) afin de déplacer ledit bras (36).
     
    4. Mécanisme de sécurité selon la revendication 2 ou 3, comportant en outre un support (38, 40) de loquet disposé dans ladite pièce moulée principale (12) et recevant de façon coulissante ledit bras (36) tandis qu'il se déplace.
     
    5. Mécanisme de sécurité selon l'une au moins des revendications 2 à 4, ladite butée (20) dudit loquet (22) formant un loquet monobloc en L conjointement avec ledit bras (36).
     
    6. Mécanisme de sécurité selon l'une au moins des revendications 2 à 5, ladite butée (20) et ledit bras (36) étant raccordés de façon intégrée.
     
    7. Mécanisme de sécurité selon l'une au moins des revendications précédentes, comportant en outre une gâchette (24) susceptible d'être actionnée, reliée de manière fonctionnelle audit plongeur (14) afin d'introduire ledit plongeur dans ladite pièce moulée principale (12).
     
    8. Mécanisme de sécurité selon l'une au moins des revendications précédentes, comportant en outre une chambre (34) destinée à loger un combustible pour briquet sous forme de fluide inflammable, une valve (26) pouvant être ouverte pour permettre au combustible de quitter ladite chambre (34).
     
    9. Mécanisme de sécurité selon la revendication 8, comportant en outre un levier (28) susceptible d'être actionné afin d'ouvrir ladite valve (26), et la gâchette (24) comprenant une partie qui s'appuie contre ledit levier (28) et actionne ledit levier afin d'ouvrir ladite valve (26) lorsque ladite gâchette (24) est actionnée afin d'introduire ledit plongeur (14) dans ladite pièce moulée principale (12).
     
    10. Mécanisme de sécurité selon l'une au moins des revendications 2 à 9, ledit bras (36) s'étendant de l'intérieur à l'extérieur de ladite pièce moulée principale (12).
     
    11. En Combinaison :

    briquet comportant un boîtier (11) ; et

    un mécanisme de sécurité selon l'une quelconque des revendications précédentes dans le boîtier.


     
    12. Combinaison selon la revendication 11, comportant en outre un ressort (44) sollicitant normalement la butée (20) vers la position d'arrêt du plongeur.
     
    13. Combinaison selon la revendication 12, comportant en outre une butée dans ledit boîtier (11), un arrêtoir (42) disposé sur ledit bras (36) et mobile avec celui-ci, et le ressort (44) disposé entre ledit arrêtoir (42) et ledit support (38, 40) de loquet, le ressort (44) sollicitant normalement ledit arrêtoir (42) pour engager ladite butée dans ledit boîtier (11) ; ledit arrêtoir (42) étant placé sur ledit bras (36) de telle sorte que, ledit arrêtoir (42) coopérant avec ladite butée, ledit bras (36) actionne ledit loquet (22) vers ladite position d'arrêt, et ledit bras (36) étant mobile afin de déplacer ladite butée (20) dudit loquet (22) jusqu'à ladite position ouverte.
     




    Drawing












    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description