EP1675732A1 - Mechanical pencil - Google Patents

Mechanical pencil

Info

Publication number
EP1675732A1
EP1675732A1 EP04817287A EP04817287A EP1675732A1 EP 1675732 A1 EP1675732 A1 EP 1675732A1 EP 04817287 A EP04817287 A EP 04817287A EP 04817287 A EP04817287 A EP 04817287A EP 1675732 A1 EP1675732 A1 EP 1675732A1
Authority
EP
European Patent Office
Prior art keywords
clamp
movable member
mechanical pencil
stop
stroke
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP04817287A
Other languages
German (de)
French (fr)
Inventor
Franck Rolion
Frédéric DUCHESNE
Jeanne-Antide Bouveresse
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BIC SA
Original Assignee
BIC SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by BIC SA filed Critical BIC SA
Publication of EP1675732A1 publication Critical patent/EP1675732A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B43—WRITING OR DRAWING IMPLEMENTS; BUREAU ACCESSORIES
    • B43K—IMPLEMENTS FOR WRITING OR DRAWING
    • B43K21/00—Propelling pencils
    • B43K21/02—Writing-core feeding mechanisms
    • B43K21/22—Writing-cores gripping means, e.g. chucks
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B43—WRITING OR DRAWING IMPLEMENTS; BUREAU ACCESSORIES
    • B43K—IMPLEMENTS FOR WRITING OR DRAWING
    • B43K21/00—Propelling pencils
    • B43K21/02—Writing-core feeding mechanisms
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B43—WRITING OR DRAWING IMPLEMENTS; BUREAU ACCESSORIES
    • B43K—IMPLEMENTS FOR WRITING OR DRAWING
    • B43K21/00—Propelling pencils
    • B43K21/02—Writing-core feeding mechanisms
    • B43K21/027—Writing-core feeding mechanisms with sliding tubelike writing-core guide
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B43—WRITING OR DRAWING IMPLEMENTS; BUREAU ACCESSORIES
    • B43K—IMPLEMENTS FOR WRITING OR DRAWING
    • B43K21/00—Propelling pencils
    • B43K21/02—Writing-core feeding mechanisms
    • B43K21/16—Writing-core feeding mechanisms with stepwise feed of writing-cores

Definitions

  • the present invention relates to a mechanical pencil and more particularly to a mechanical pencil comprising a tubular body extending along a longitudinal axis between a rear end and a front end provided with an opening through which a mine is capable of exit, and a lead advance mechanism arranged in the tubular body, which comprises: - a member movable longitudinally and having a bearing surface oriented towards the front; a clamp having a tubular portion connected to the movable member, and a head capable of being clamped on the mine; - A clamping ring movable longitudinally relative to the clamp and the tubular body, which is adapted to cooperate with the head of the clamp; an elastic element having a front end and a rear end in abutment against the bearing surface of the movable member, said elastic element being adapted to urge the clamping ring against the head of the clamp when the advance mechanism is in rest position.
  • the body of the mechanical pencil includes an additional elastic means, the rear end of which bears on the body of the mechanical pencil.
  • lead and the front end bears on the clamping ring or optionally on a sleeve bearing on the clamping ring, so as to allow a backward movement of the advance mechanism assembly, c ' is to say including the moving part.
  • the movable member is a tube which forms a mine reservoir and into which the rear end of the pliers is force fitted.
  • this additional elastic means which may consist of a compression spring or an elastically deformable tube portion, increases the number of parts, complicates the assembly of the mechanical pencil and increases the space required in the co- tubular rps to house the entire mechanism, which a. a negative effect on the manufacturing cost.
  • the purpose of the present invention is to overcome the drawbacks mentioned above by proposing a mechanical pencil authorizing a retraction of the mine, which has a simplified structure, in particular in order to reduce its manufacturing cost.
  • the recoil of the mine must be elastic, so that it returns to the writing position as soon as the user ceases to exert excessive pressure thereon.
  • the subject of the present invention is a mechanical pencil of the aforementioned type, characterized in that a bush, movable longitudinally relative to the clamp and to the body, is arranged between the clamping ring and the front end of - The elastic element, in that the clamp is movable longitudinally relative to the movable member over a determined stroke, called the recoil stroke, and in that the body has a front stop adapted to limit the forward movement from the socket.
  • this arrangement allows a retreat of the mine without necessarily causing a retreat of the movable member, which has the advantage of not having an effect on the control means of the movable member and in particular not to cause them to move towards the outside of the body, whether it be a push button arranged at the rear end of the body or a side button movable in a radial direction of the body.
  • the front stop is formed by a radially inner rim which cooperates with a peripheral portion of the front end of the sleeve;
  • the elastic element is a helical compression spring;
  • the tubular portion of the clamp has from its rear end first and second radially outer edges, and the front end of the movable member has an opening through which the clamp slides between the first and second edges, said first and second edges being longitudinally spaced to limit this sliding of the clamp to a value equal to the recoil stroke;
  • the tubular portion of the clamp has a frustoconical portion extending from the first flange to the rear end of the clamp, to allow mounting of the clamp by snap-fastening in the movable member.
  • the body has a rear stop adapted to cooperate with a complementary stop of the movable member and limit the rearward movement of the member movable, the longitudinal distance between the front stop of the body and said rear stop being adapted so that the clamping ring keeps the clamp tight under the action of the sleeve when the advance mechanism is in the rest position;
  • the rear stop is formed by a radially inner rim of the body, which cooperates with a radially outer shoulder of the movable member.
  • the body has a window extending longitudinally to a rear end, and the movable member has a lug protruding into the window, the rear end of said window forming the rear stop; at least one elastically deformable compensation member is arranged between the front stop of the body and the sleeve, or between the rear stop of the body and the complementary stop of the movable member, in order to compensate for any play between the advance mechanism and the body stops;
  • the compensating member comprises at least one elastically deformable tab in a longitudinal direction and integral with the body;
  • the body has a recoil position adapted to limit the displacement of the clamping bar towards the rear, from the rest position of the advance mechanism, to a value at most equal to the recoil stroke of the pliers, so as to increase the tightening of the pliers and to prevent the mine from sliding;
  • the back-up stop is formed by at least one pin integral with the body and extending radially inwards between the sleeve and the movable member, said
  • FIG. 1 is a view in longitudinal section of a door -mine according to a first embodiment of the invention and in which a mine advance mechanism is in the rest position;
  • Figure 2 is an enlarged view of a front portion of the mechanical pencil shown in Figure 1;
  • FIG. 4 is a view similar to FIG. 2, in which the advance mechanism has made a second stroke towards the front;
  • Figure 5 is a view similar to Figure 2, in which-, the advance mechanism has made a backward stroke 1 rearward;
  • Figure 6 enlarged in perspective of an element of the mechanical pencil shown in Figure 1;
  • - Figure 7 is a partial view of a half longitudinal section of a mechanical pencil according to, a second embodiment of the invention and in which the advance mechanism is in the rest position;
  • Figure 8 is a view similar to Figure 7, in which the advance mechanism has made a back stroke.
  • the same references have been kept to designate identical or similar elements.
  • Figures 1 to 5 is shown a first embodiment of a mechanical pencil.
  • the mechanical pencil 1 comprises a tubular body 2 which extends along a longitudinal axis X between a front end 2a and a rear end 2b.
  • the body 2 is formed of a tube 3 and a tip 4 arranged at the front end of the body 2.
  • the tip 4 has at its front end an opening through which a lead guide tip 5 which is freely mounted sliding in a bore 4a of the tip 4.
  • the guide tip 5 accompanies the exit of the mine 6 to avoid breakage of the mine.
  • the wear of the lead reaches the end of the guide tip, the latter touches the paper and makes a backward movement, which releases the end of the lead and allows writing to continue.
  • a side button 7 is mounted through a rectangular window 8 formed in the radial wall of the tubular body 2 and extending along the longitudinal axis X.
  • the side button 7 has an actuation surface 9 oriented radially towards the outside.
  • the side button 7 comprises a first pair of cams 11 arranged opposite the face of one actuator 9 to the front end of the side button having a cross section U.
  • the rear end 7b of the side switch section transverse, also in U, has a second pair of cams 12, analogously to one front end. It will be noted that the first pair of cams 11 is spaced from the second pair of cams 12 by a significant distance measured along the axis X, which is close to the longitudinal length of the actuation face 9 of the side button 7.
  • the part of the side button 7 located inside the body 2 comprises lugs, and in particular a lug 16 which projects towards the rear end 2b of the body 2, which cooperate with the inner periphery of the window 8 and thus prevent the exit complete with the side button 7 of the tubular body 2.
  • a feed mechanism which comprises a movable member 20, a clamp 30, a bush 40, a clamping ring 18 and a compression spring 19 disposed between the movable member 20 and the sleeve 40.
  • the rear end 20b of the mobile organ is equipped with an element 46 projecting through the rear end 2b of the body.
  • the element 46 comprises a tubular part, a clip and a cylindrical recess in which is mounted an eraser 47.
  • the element 46 and the eraser 47 form a rear button which makes it possible to move the movable member 20 forward.
  • L movable member 20 is slidably mounted along the longitudinal axis X in the tubular body 2.
  • the movable member 20 comprises a front part 21 which forms the front end 20a of the movable member and a main part 22 fixed to the front part 21.
  • the main part 22 comprises a first portion located on the side of the front end 20a of the movable member, which will be detailed below, and a hollow rear portion 22b which forms a reservoir of mines. But it is perfectly possible that the mine reservoir is formed by an independent piece fixed to the movable member 20.
  • the front piece 21 of the movable member has a recess oriented towards the front end 2a of the body, the bottom 21a of which forms a bearing surface for the spring 19.
  • the portion front of the main part 22 of the movable member 20 has a first pair of identical ramps 23 arranged on the side of the front end 20a of the movable member.
  • the first ramps 23 are located on either side of a central duct 24 allowing the passage of the mines from the reservoir 22b towards the clamp 30.
  • Each first ramp 23 has a rectilinear surface inclined relative to the longitudinal axis X, oriented towards the rear of the body 2.
  • the first pair of cams 11 cooperates with the first pair of ramps 23 and causes a displacement towards the front end 2a of the movable member 20.
  • a bearing 25 parallel to the longitudinal axis X is formed on the face of the movable member 20 opposite the side button 7. The bearing 25 s 'extends on either side of the conduit 24 and is positioned longitudinally so that the second pair of cams 12 of the side button 7 can bear on the latter when the side button is in the rest position.
  • a second pair of ramps 26 immediately follows the rear end of the bearing 25. The second ramps 26 are located on either side of the mine tank and are inclined relative to the longitudinal axis in a manner similar to the first ramps 23.
  • the second ramps 26 are spaced longitudinally of the first ramps 23 so that the second pair of cams 12 faces the second ramps 26 when the side button 7 has performed a first tilting movement and is in the position shown in FIG. 3.
  • the body 2 of the mechanical pencil has a flange 27 which extends radially inwards and has a surface 27b parallel to the longitudinal axis X in look from window 8 of the body, against which a protruding boss
  • the front end of the rim 27 has a transverse surface 27a oriented towards the front which forms a stop, known as the rear stop, against which a radially external shoulder 29 of the movable member abuts.
  • the rear stop 27a thus makes it possible to limit the recoil of the movable member 20.
  • the clamp 30 comprises a tubular portion 31 and a head 32 which cooperates in known manner with the clamping ring 18 to immobilize the mine 6. In the modes of embodiment shown, the tubular portion 31 extends from a rear end 31b to the head 32 located on the side of the front end
  • the tubular portion 31 has from its rear end 31b a first flange 33 projecting outwards in a radial direction perpendicular to the longitudinal axis X, and a second flange 34 also radially exterior.
  • the tubular portion 31 of the clamp has a frustoconical portion 35 extending from the first flange
  • the clamp can be mounted through the opening 21c of the movable member 20 by snap-fastening.
  • the front end of the movable member 20, formed by the front part 21, has an opening 21c through which the tubular portion 31 of the clamp is slidably mounted along the longitudinal axis X between the first flange 33 and the second flange 34.
  • the first 33 and second 34 flanges are spaced apart longitudinally so as to allow longitudinal sliding of the clamp 30 by relative to the movable member 20 over a determined length hereinafter called "recoil stroke".
  • the sleeve 40 is slidably mounted in the body 2 of the mechanical pencil and it is also movable longitudinally relative to the clamp 30.
  • the sleeve 40 is a cylindrical piece which has a central opening 41 through which passes the tubular portion 31 of the clamp, a front end face 42 and a rear end face 43 of planar annular shape.
  • the socket 40 could have a different shape, such as for example a cup shape.
  • the front annular face 42 of the sleeve extends over a radial distance sufficient to come to bear both against the clamping ring 18 and against a radially internal rim of the body 2 which is formed by the rear end 4b of the tip 4.
  • the rear end 4b of the tip thus forms a stop integral with the body 2, called the front stop, which limits the displacement of the bush 40 towards the front end 2a of the body when the peripheral portion of the end before 43 of the ring comes into contact.
  • the spring 19 has a front end 19a bearing against the rear face 43 of the bushing and a rear end 19b bearing against the bearing surface 21a of the movable member, so that the spring keeps the bushing as far apart as possible 40 of the movable member 20. It will be noted that the distance between these two parts is limited by the clamp 30 whose first flange 33 cooperates with the opening 21c of the movable member, and the head 32 of which limits the forward movement of the ring 18, which itself limits the forward movement of the bush 40.
  • the advance mechanism forms thus a unitary assembly which can be pre-assembled before its introduction into the body 2 of the mechanical pencil by the front end of the tube 3, which facilitates the assembly of the mechanical pencil. It is preferable that the front stop 4b and the rear stop 27a of the body 2 be sufficiently spaced to allow maximum distance between the bush 40 and the movable member 20 when the advance mechanism is in the rest position. In fact, if the distance between the front 4b and rear 21a stops is not sufficient, the bush 40 cannot push the ring 18 on the head 32 sufficiently advanced to guarantee maximum clamping of the clamp head on the lead 6.
  • the front stops 4b and rear 21a are spaced so that the advance mechanism is mounted with a slight longitudinal play in the body 2.
  • such play can have a negative effect on the quality of the mechanical pencil perceived by the user, since a clicking noise can be caused by the movement of the advance mechanism. in body 2 when the user shakes the mechanical pencil.
  • the compensation member 50 is arranged between the front stop 4b of the body and the sleeve 40, but it is clear that the compensation member could be arranged between the rear stop 27a of the body and the complementary stop 29 of the movable member.
  • the compensating member 50 is formed by two legs 51 in an arc which can be elastically deformed towards the front end 2a. The ends of the legs 51 are integral with the tip 4, so that the legs 51 form only one piece obtained by molding with the tip 4. But of course, the compensation member 50 could be formed by an independent piece , such as a very short compression spring.
  • the tube 3 forming the body of the mechanical pencil comprises two diametrically opposite pins 52, which extend radially inside the body 2 between the sleeve 40 and the movable member 20.
  • the pins 52 are arranged at a distance, measured from the rear face 43 of the sleeve in the rest position, which is equal to or slightly less than the recoil stroke of the clamp 30 relative to the movable member 20.
  • the spring 19 is a helical compression spring made of metal. This type of spring has the advantage of being able to be compressed over a large stroke while maintaining a constant stiffness. In addition, it is a standard part produced in large quantities and whose stiffness is perfectly known and constant.
  • the spring 19 will also be chosen as a function of the dimensions of the advance mechanism, and in particular of the recoil stroke, so as to exert a pressure of between 5 and 10 newtons, and preferably 8 newtons, when the clamp has moved backward equal to the effective mine recoil stroke.
  • the operation of the mechanical pencil described above will be explained using FIGS. 2 to 5.
  • the clamping ring 18 maintains the head 32 of the pliers tightened on the lead 6 thanks to the action of the spring 19.
  • the spring 19 exerts, on the one hand, a rearward pull on the clamp, through the opening 21c of the movable member which is in support against the first flange 33 of the clamp, and on the other hand, a push forward on the clamping ring 18, via the sleeve 40.
  • the lead 6 In the rest position, that is to say say outside of any actuation of the side button 7 or rear button formed by the element 46 and the rubber 47, the lead 6 is therefore kept blocked in the head 32 of the pliers.
  • a first forward movement of the movable member 20 is obtained to a position shown in FIG. 3, by cooperation of the first pair of cams 11 of the button on the first pair of ramps 23 of the movable member, the second pair of cams 12 remaining supported on the bearing 25.
  • this first movement one can distinguish two races of the movable member.
  • a first stroke of approximately 2 mm during which the opening 21c of the movable member slides along the tubular portion of the clamp from the first flange 33 to the second flange 34, the clamp 30 remaining stationary during this first race.
  • a second stroke called the advance stroke, during which the opening 21c of the movable member is in abutment against the second flange 34 and the clamp 30 moves forward.
  • this second stroke the clamping ring 18 accompanies the movement of the head 32 of the pliers and consequently the mine is displaced by a corresponding value.
  • the guide tip 5 remains stationary in the bore 4a of the tip, due to a friction force between the guide tip-mine 5 and the tip 4 greater than the friction force between the guide tip 5 and the lead 6.
  • this advance stroke is substantially equal to one millimeter, that is to say approximately half of the reverse stroke.
  • the head 32 of the pliers comes to bear against the rear end of the guide tip 5, which causes the output of the latter accompanied by the mine 6.
  • the latter advances with the mine guide tip 5 due to the friction force existing between the mine guide tip and the mine.
  • the spring 19 pushes the movable member 20 backwards, which results in a return of the side button to the position due to the action of the first 23 and second 26 pairs of ramps on the first 11 and second 12 pairs of cams.
  • the clamp 30 also performs a movement towards the rear, but the head 32 remains open over almost the entire length of this movement and the lead 6 makes almost no movement. backward movement, so that the guide tip 5 remains in the extended position.
  • the entire advancing mechanism returns to the rest position, as shown in FIG. 2, and the head 32 of the pliers again immobilizes the mine 6, but the mine and the guide tip 5 remains out as shown in Figure 4, so that the mechanical pencil is ready to be used.
  • the advance of the mine described above is obtained by actuating the side button 7, but of course, actuation of the rear button would cause a similar advance of the mine.
  • the effective recoil stroke of the mine is equal to the recoil stroke of the clamp relative to the movable member, but the clamping force of the clamp on the mine does not increase more when the second rim 34 abuts against the opening 21c of the movable member.
  • the effective recoil of the mine is preferably limited to a value slightly less than the recoil stroke.
  • the clamping force of the head 32 of the pliers on the mine increases significantly because the ring 18 is then immobilized. This avoids the mine sliding in the head 32 of the pliers.
  • FIGs 7 and 8 there is shown a second embodiment of a mechanical pencil according to the invention.
  • the tubular body 2 is also formed of a tube 3 and a tip 4, however, the tip 4 does not have a guide tip.
  • the advance mechanism comprises, as for the first embodiment, a movable member 20, a clamp 30, a clamping ring 18, a bush 40 and a spring 19.
  • the advance mechanism is controlled only by a rear button not shown in Figures 7 and 8.
  • the movable member 20 is formed of a single front piece 21 which has a frustoconical bearing face 21a, but generally oriented towards the front, and against which is supported on the rear end 19b of the spring.
  • the part 21 of the movable member has at its front end 20a an opening 21c through which is movably mounted a clamp 30 quite similar to the clamp of the first embodiment, so that the tubular portion 31 of the clamp slides in the opening 21c between a first flange 33 and a second flange 34 on a determined stroke called 'recoil'.
  • the movable member 20 has a lug 53 which projects outwards in a window 54 extending longitudinally in the tube 3 between a front end 54a and a rear end 54b.
  • the rear end 54b of the window 54 forms a rear stop of the body which cooperates with a stop complementary to the movable member formed by the lug 53, so as to limit the rearward movement of the movable member 20.
  • the sleeve 40 is formed of a slightly conical washer whose movement towards the front is limited by a stop 3a formed by a radially internal rim of the tube 3, which has a first face 55 generally oriented towards the rear of the body.
  • the clamping sleeve 18 of this second embodiment has a radially outer shoulder 18a and the radially inner rim 3a of the tube has a face 56 oriented towards the front end 2a of the body.
  • the face 56 forms a recoil stop adapted to limit the backward recoil of the clamping ring 18.
  • the rear stop 54b and the front stop 55 of the body 2 must be sufficiently spaced longitudinally , so that the advance mechanism firmly immobilizes the lead 6 when it is in the rest position shown in FIG. 7, that is to say that the sleeve 40 must push the clamping ring 18 sufficiently towards the before so that the head 32 of the pliers grips the mine.
  • the advance of the pencil 6 is controlled by pressing the rear button of the mechanical pencil, which causes the movable member 20 to move forwards, during which the opening 21c abuts against the second edge 34 of the pliers, then causes the pliers to move forward until the clamping ring 18 abuts against a rim 4c of the point and causes the head 32 of the pliers to open.
  • the retraction of the clamp in the open position is then ensured by the spring 19.
  • the advance of the mine in this second embodiment, is therefore quite similar to that of the first mode, although the tip 4 does not include advanced mine guide.
  • the clamp 30 moves backwards by sliding in the opening 21c of the movable member and compressing the spring 19.
  • the movable member 20 remains abutted against the rear stop 54b of the body.
  • the shoulder 18a of the ring comes against the recoil stop 56 of the body, which increases the tightening of the ring 18 on the head of the pliers 32 and This makes it very difficult for the lead 6 to slide in the head 32.
  • the second rim 34 of the clamp is not in contact with the opening 21c of the movable member when the clamp is in the maximum recoil position. Therefore, for 'this embodiment, the effective stroke of reversing the lead 6 is smaller than the backward stroke of the gripper 30 relative to the movable member.

Landscapes

  • Mechanical Pencils And Projecting And Retracting Systems Therefor, And Multi-System Writing Instruments (AREA)

Abstract

The invention relates to a mechanical pencil, comprising a body (2) which extends between a rear end and a front end (2a) and a lead feeding mechanism which comprises: a moving member (20), having a bearing surface (21a), a clamp (30), connected to the moving member, a clamping ring (18) which cooperates with the clamp head (32) and an elastic element (19), having a rear end (19b) which is supported on the bearing surface (21a). Said elastic element tensions the ring (18) against the head (32) when the feeding mechanism is at rest. A moving sleeve (40) is arranged between the clamping ring (40) and the front end (19a) of the elastic element. The clamp (30) is movable in relation to the moving member (20) along a determined stroke length. The body (2) has a stop (4b) for limiting the forward movement of the sleeve (40).

Description

PORTE -MINE MINE CARRIER
La présente invention se rapporte à un porte-mine et plus particulièrement à un porte-mine comprenant un corps tubulaire s ' étendant selon un axe longitudinal entre une extrémité arrière et une extrémité avant munie d'une ouverture à travers laquelle une mine est susceptible de sortir, et un mécanisme d'avance de la mine agencé dans le corps tubulaire, qui comporte : - un organe mobile longitudinalement et présentant une surface d'appui orientée vers l'avant ; une pince présentant une portion tubulaire reliée à l'organe mobile, et une tête susceptible d'être serrée sur la mine ; - une bague de serrage mobile longitudinalement par rapport à la pince et au corps tubulaire, qui est adaptée pour coopérer avec la tête de la pince ; un élément élastique présentant une extrémité avant et une extrémité arrière en appui contre la surface d'appui de l'organe mobile, ledit élément élastique étant adapté pour solliciter la bague de serrage contre la tête de la pince lorsque le mécanisme d'avance est en position de repos . Il est connu, pour les porte-mine de ce type, de prévoir la possibilité d'un recul de la mine lorsque l'utilisateur exerce une pression trop importante sur celle-ci et afin d'éviter que la mine ne se brise. Pour obtenir un recul de la mine, et comme par exemple décrit dans le document US-A-4, 371, 277, le corps du porte-mine comprend un moyen élastique supplémentaire dont l'extrémité arrière prend appui sur le corps du porte-mine et 1 ' extrémité avant prend appui sur la bague de serrage ou éventuellement sur un manchon en appui sur la bague de serrage, de manière à autoriser un mouvement de recul vers l'arrière de l'ensemble du mécanisme d'avance, c'est-à-dire y compris l'organe mobile. Le plus souvent, l'organe mobile est un tube qui forme un réservoir de mines et dans lequel l'extrémité arrière de la pince est emmanchée à force. Toutefois, ce moyen élastique supplémentaire, qui peut être constitué d'un ressort de compression ou d'une portion de tube élastiquement déformable, accroît le nombre de pièces, complique le montage du porte-mine et augmente l'espace nécessaire dans le co-rps tubulaire pour loger l'ensemble du mécanisme, ce qui a. un effet néfaste sur le coût de fabrication. La présente invention a pour but de pallier les inconvénients mentionnés ci-dessus en proposant un portemine autorisant un recul de la mine, qui présente une structure simplifiée, afin notamment de réduire son coût de fabrication. Bien entendu, le recul de la mine doit être élastique, de manière à ce que celle-ci revienne en position d'écriture dès que l'utilisateur cesse d'exercer une pression excessive sur celle-ci. A cet effet, la présente invention a pour objet un porte-mine du type précité, caractérisé en ce qu'une douille, mobile longitudinalement par rapport à la pince et au corps, est agencée entre la bague de serrage et 1 ' extrémité avant de- l'élément élastique, en ce que la pince est mobile longitudinalement par rapport à l'organe mobile sur une course déterminée, dite course de recul, et en ce que le corps présente une butée avant adaptée pour limiter le déplacement vers l'avant de la douille. Grâce à cette disposition, il suffit d'un seul et unique élément élastique pour à la fois serrer la tête de la pince à l'aide de la bague et permettre un recul élastique de la mine lorsque l'utilisateur exerce une pression excessive. Ceci permet de réduire le nombre de pièces et l'encombrement du mécanisme du porte-mine. On notera également que cette disposition permet d'autoriser un recul de la mine sans nécessairement entraîner un recul de l'organe mobile, ce qui présente l'avantage de ne pas avoir d'effet sur les moyens de commande de l'organe mobile et notamment de ne pas provoquer un déplacement de ceux-ci vers l'extérieur du corps, qu'il s'agisse d'un bouton-poussoir agencé à l'extrémité arrière du corps ou d'un bouton latéral mobile selon une direction radiale du corps. Dans des modes préférés de réalisation de la présente invention, on peut avoir recours, en outre, à l'une et/ou à l'autre des dispositions suivantes dans lesquelles : - la butée avant est formée par un rebord radialement intérieur qui coopère avec une portion périphérique de l'extrémité avant de la douille ; l'élément élastique est un ressort de compression hélicoïdal ; - la portion tubulaire de la pince présente depuis son extrémité arrière un premier et un deuxième rebords radialement extérieurs, et l'extrémité avant de l'organe mobile présente une ouverture à travers laquelle la pince coulisse entre les premier et deuxième rebords, lesdits premier et deuxième rebords étant longitudinalement espacés pour limiter ce coulissement de la pince à une valeur égale à la course de recul ; la portion tubulaire de la pince présente une portion tronconique s'étendant depuis le premier rebord jusqu'à l'extrémité arrière de la pince, afin de permettre un montage de la pince par encliquetage dans l'organe mobile. le corps présente une butée arrière adaptée pour coopérer avec une butée complémentaire de l'organe mobile et limiter le déplacement vers l'arrière de l'organe mobile, la distance longitudinale entre la butée avant du corps et ladite butée arrière étant adaptée pour que la bague de serrage maintienne la pince serrée sous l'action de la douille lorsque le mécanisme d' avance est en position de repos ; la butée arrière est formée par un rebord radialement intérieur du corps, qui coopère avec un épaulement radialement extérieur de l'organe mobile. le corps présente une fenêtre s 'étendant longitudinalement jusqu'à une extrémité arrière, et l'organe mobile présente un ergot faisant saillie dans la fenêtre, l'extrémité arrière de ladite fenêtre formant la butée arrière ; au moins un organe de compensation elastiquement deformable est agencé entre la butée avant du corps et la douille, ou entre la butée arrière du corps et la butée complémentaire de l'organe mobile, afin de compenser un jeu éventuel entre le mécanisme d'avance et les butées du corps ; - l'organe de compensation comprend au moins une patte elastiquement deformable selon une direction longitudinale et venue de matière avec le corps ; le corps présente une bmtée de recul adaptée pour limiter le déplacement de la ba.gue de serrage vers l'arrière, à partir de la position de repos du mécanisme d'avance, à une valeur au plus égale â la course de recul de la pince, de manière à augmenter le serrage de la pince et éviter un glissement de la mine ; la butée de recul est formée par au moins un pion solidaire du corps et s'étendant radialement vers l'intérieur entre la douille et l'organe mobile, ledit pion étant adapté pour limiter le déplacement vers l'arrière de la douille ; la butée de recul est formée par un rebord radialement intérieur du corps, qui est adapté pour coopérer avec un épaulement radialement extérieur de la bague de serrage ; la pince est susceptible d'entraîner la mine vers l'avant sur une course déterminée, dite course d'avance, ladite course d'avance étant sensiblement égale à la moitié de la course de recul. - l'élément élastique est adapté pour exercer une pression sur la douille comprise entre 2 et 5 newtons, et de préférence 3 newtons, lorsque le mécanisme d'avance est en position de repos, et une pression comprise entre 5 et 10 newtons, et de préférence de 8 newtons, lorsque la pince a effectué un déplacement vers l'arrière sensiblement égal à la course de recul. D'autres caractéristiques et avantages de l'invention apparaîtront au cours de la description qui va suivre, donnée à titre d'exemple non limitatif, en référence aux dessins annexés dans lesquels : la figure 1 est une vue en coupe longitudinale d'un porte-mine selon un premier mode de réalisation de l'invention et dans laquelle un mécanisme d'avance de mine est en position de repos ; la figure 2 est une vue agrandie d'une portion avant du porte-mine représenté à la figure 1 ; la figure 3 et une vue analogue à la figure 2 , dans laquelle le mécanisme d'avance a effectué une première course vers 1 ' avant ; la figure 4 est une vue analogue à la figure 2, dans laquelle le mécanisme d'avance a effectué une deuxième course vers 1 ' avant ; la figure 5 est une vue analogue à la figure 2, dans laquelle-, le mécanisme d'avance a effectué une course de recul vers 1 ' arrière ; la figure 6 agrandie en perspective d'un élément du porte-mine représenté à la figure 1 ; - la figure 7 est une vue partielle d'une demi- coupe longitudinale d'un porte-mine selon, un deuxième mode de réalisation de l'invention et dans laquelle le mécanisme d'avance est en position de repos ; la figure 8 est une vue analogue à la figure 7, dans laquelle le mécanisme d'avance a effectué une course de recul . Sur les différentes figures, on a conservé les mêmes références pour désigner des éléments identiques ou similaires. Aux figures 1 à 5 est représenté un premier mode de réalisation d'un porte-mine. Le porte-mine 1 comprend un corps tubulaire 2 qui s ' étend selon un axe longitudinal X entre une extrémité avant 2a et une extrémité arrière 2b. Le corps 2 est formé d'un tube 3 et d'une pointe 4 agencée à 1 ' extrémité avant du corps 2. La pointe 4 présente à son extrémité avant une ouverture à travers laquelle passe une pointe guide-mine 5 qui est montée librement coulissante dans un alésage 4a de la pointe 4. La pointe guide-mine 5 accompagne la sortie de la mine 6 pour éviter une cassure de la mine. Lorsque l'usure de la mine atteint l'extrémité de la pointe guide- mine, celle-ci touche le papier et effectue un mouvement de recul , ce qui dégage 1 ' extrémité de la mine et permet de poursuivre l'écriture. Un bouton latéral 7 est monté au travers d'une fenêtre rectangulaire 8 formée dans la paroi radiale du corps tubulaire 2 et s 'étendant selon l'axe longitudinal X. Le bouton latéral 7 présente une surface d' actionnement 9 orientée radialement vers l'extérieur. Le bouton latéral 7 comporte une première paire de cames 11 agencées de manière opposée à la face d1 actionnement 9 à l'extrémité avant du bouton latéral qui présente une section transversale en U. L'extrémité arrière 7b du bouton latéral de section transversale, également en U, présente une deuxième paire de cames 12 , de manière analogue à 1 ' extrémité avant . On notera que la première paire de cames 11 est espacée de la deuxième paire de cames 12 d'une distance significative mesurée selon l'axe X, qui est proche de la longueur longitudinale de la face d' actionnement 9 du bouton latéral 7. La partie du bouton latéral 7 située à 1 ' intérieur du corps 2 comporte des ergots, et notamment un ergot 16 qui est saillant vers l'extrémité arrière 2b du corps 2, qui coopèrent avec le pourtour intérieur de la fenêtre 8 et empêchent ainsi la sortie complète du bouton latéral 7 du corps tubulaire 2. A 1 ' intérieur du corps tubulaire 2 est agencé un mécanisme d'avance qui comprend un organe mobile 20, une pince 30, une douille 40, une bague de serrage 18 et un ressort de compression 19 disposé entre l'organe mobile 20 et la douille 40. L'extrémité arrière 20b de l'oαrgane mobile est équipée d'un élément 46 faisant saillie à travers l'extrémité arrière 2b du corps. L'élément 46 comprend une partie tubulaire, une agrafe et un évidement cylindrique dans lequel est montée une gomme 47. L'élément 46 et la gomme 47 forment un bouton arrière qui permet de déplacer vers l'avant l'organe mobile 20. L'organe mobile 20 est monté coulissant selon l'axe longitudinal X dans le corps tubulaire 2. Dans le mode de réalisation représenté, l'organe mobile 20 comprend une pièce avant 21 qui forme l'extrémité avant 20a de l'organe mobile et une pièce principale 22 fixée à la pièce avant 21. La pièce principale 22 comporte une première portion située du côté de l'extrémité avant 20a de l'organe mobile, qui sera détaillée ci-après, et une portion arrière creuse 22b qui forme un réservoir de mines . Mais il est parfaitement possible que le réservoir de mines soit formé par une pièce indépendante fixée à l'organe mobile 20. La pièce avant 21 de l'organe mobile présente un creux orienté vers l'extrémité avant 2a du corps dont le fond 21a forme une surface d'appui pour le ressort 19. La portion avant de la pièce principale 22 de l'organe mobile 20 présente une première paire de rampes 23 identiques et agencées du côté de l'extrémité avant 20a de l'organe mobile. Les premières rampes 23 sont situées de part et d'autres d'un conduit central 24 permettant le passage des mines depuis le réservoir 22b vers la pince 30. Chaque première rampe 23 présente une surface rectiligne inclinée par rapport à l'axe longitudinal X, orientée vers 1 ' arrière du corps 2. Ainsi, lorsque l'on exerce une pression sur le bouton latéral 7 à partir de la position de repos représentée aux figures 1 et 2 , la première paire de cames 11 coopère avec la première paire de rampes 23 et entraîne un déplacement vers l'extrémité avant 2a de l'organe mobile 20. Un palier 25 parallèle à l'axe longitudinal X est formé sur la face de l'organe mobile 20 en regard du bouton latéral 7. Le palier 25 s'étend de part et d'autre du conduit 24 et est positionné longitudinalement de manière -à ce que la deuxième paire de cames 12 du bouton latéral 7 puisse prendre appui sur celui-ci lorsque le bouton latéral est en position de repos. Une deuxième paire de rampes 26 suit immédiatement l'extrémité arrière du palier 25. Les deuxièmes rampes 26 sont situées de part et d'autre du réservoir de mines et sont inclinées par rapport à l'axe longitudinal de manière analogue aux premières rampes 23. Les deuxièmes rampes 26 sont espacées longitudinalement des premières rampes 23 de manière à ce que la deuxième paire de cames 12 soit en regard des deuxièmes rampes 26 lorsque le bouton latéral 7 a effectué un premier mouvement de basculement et se trouve dans la position représentée à la figure 3. Le corps 2 du porte-mine comporte un rebord 27 qui s'étend radialement vers l'intérieur et présente une surface 27b parallèle à l'axe longitudinal X en regard de la fenêtre 8 du corps, contre laquelle un bossage saillantThe present invention relates to a mechanical pencil and more particularly to a mechanical pencil comprising a tubular body extending along a longitudinal axis between a rear end and a front end provided with an opening through which a mine is capable of exit, and a lead advance mechanism arranged in the tubular body, which comprises: - a member movable longitudinally and having a bearing surface oriented towards the front; a clamp having a tubular portion connected to the movable member, and a head capable of being clamped on the mine; - A clamping ring movable longitudinally relative to the clamp and the tubular body, which is adapted to cooperate with the head of the clamp; an elastic element having a front end and a rear end in abutment against the bearing surface of the movable member, said elastic element being adapted to urge the clamping ring against the head of the clamp when the advance mechanism is in rest position. It is known, for mechanical pencils of this type, to provide for the possibility of a retraction of the mine when the user exerts too great a pressure thereon and in order to prevent the mine from breaking. To obtain a retraction of the mine, and as for example described in document US-A-4, 371, 277, the body of the mechanical pencil includes an additional elastic means, the rear end of which bears on the body of the mechanical pencil. lead and the front end bears on the clamping ring or optionally on a sleeve bearing on the clamping ring, so as to allow a backward movement of the advance mechanism assembly, c ' is to say including the moving part. Most often, the movable member is a tube which forms a mine reservoir and into which the rear end of the pliers is force fitted. However, this additional elastic means, which may consist of a compression spring or an elastically deformable tube portion, increases the number of parts, complicates the assembly of the mechanical pencil and increases the space required in the co- tubular rps to house the entire mechanism, which a. a negative effect on the manufacturing cost. The purpose of the present invention is to overcome the drawbacks mentioned above by proposing a mechanical pencil authorizing a retraction of the mine, which has a simplified structure, in particular in order to reduce its manufacturing cost. Of course, the recoil of the mine must be elastic, so that it returns to the writing position as soon as the user ceases to exert excessive pressure thereon. To this end, the subject of the present invention is a mechanical pencil of the aforementioned type, characterized in that a bush, movable longitudinally relative to the clamp and to the body, is arranged between the clamping ring and the front end of - The elastic element, in that the clamp is movable longitudinally relative to the movable member over a determined stroke, called the recoil stroke, and in that the body has a front stop adapted to limit the forward movement from the socket. Thanks to this arrangement, a single elastic element is sufficient to both tighten the head of the pliers using the ring and allow an elastic retraction of the lead when the user exerts excessive pressure. This reduces the number of parts and the size of the mechanical pencil mechanism. It will also be noted that this arrangement allows a retreat of the mine without necessarily causing a retreat of the movable member, which has the advantage of not having an effect on the control means of the movable member and in particular not to cause them to move towards the outside of the body, whether it be a push button arranged at the rear end of the body or a side button movable in a radial direction of the body. In preferred embodiments of the present invention, it is also possible to have recourse to one and / or the other of the following arrangements in which: the front stop is formed by a radially inner rim which cooperates with a peripheral portion of the front end of the sleeve; the elastic element is a helical compression spring; the tubular portion of the clamp has from its rear end first and second radially outer edges, and the front end of the movable member has an opening through which the clamp slides between the first and second edges, said first and second edges being longitudinally spaced to limit this sliding of the clamp to a value equal to the recoil stroke; the tubular portion of the clamp has a frustoconical portion extending from the first flange to the rear end of the clamp, to allow mounting of the clamp by snap-fastening in the movable member. the body has a rear stop adapted to cooperate with a complementary stop of the movable member and limit the rearward movement of the member movable, the longitudinal distance between the front stop of the body and said rear stop being adapted so that the clamping ring keeps the clamp tight under the action of the sleeve when the advance mechanism is in the rest position; the rear stop is formed by a radially inner rim of the body, which cooperates with a radially outer shoulder of the movable member. the body has a window extending longitudinally to a rear end, and the movable member has a lug protruding into the window, the rear end of said window forming the rear stop; at least one elastically deformable compensation member is arranged between the front stop of the body and the sleeve, or between the rear stop of the body and the complementary stop of the movable member, in order to compensate for any play between the advance mechanism and the body stops; - The compensating member comprises at least one elastically deformable tab in a longitudinal direction and integral with the body; the body has a recoil position adapted to limit the displacement of the clamping bar towards the rear, from the rest position of the advance mechanism, to a value at most equal to the recoil stroke of the pliers, so as to increase the tightening of the pliers and to prevent the mine from sliding; the back-up stop is formed by at least one pin integral with the body and extending radially inwards between the sleeve and the movable member, said pin being adapted to limit the rearward movement of the sleeve; the recoil stop is formed by a radially inner rim of the body, which is suitable for cooperate with a radially outer shoulder of the clamping ring; the clamp is capable of driving the mine forward over a determined stroke, called the advance stroke, said advance stroke being substantially equal to half of the recoil stroke. the elastic element is adapted to exert pressure on the bushing between 2 and 5 newtons, and preferably 3 newtons, when the advance mechanism is in the rest position, and a pressure between 5 and 10 newtons, and preferably 8 newtons, when the clamp has moved backwards substantially equal to the recoil stroke. Other characteristics and advantages of the invention will appear during the description which follows, given by way of nonlimiting example, with reference to the appended drawings in which: FIG. 1 is a view in longitudinal section of a door -mine according to a first embodiment of the invention and in which a mine advance mechanism is in the rest position; Figure 2 is an enlarged view of a front portion of the mechanical pencil shown in Figure 1; FIG. 3 and a view similar to FIG. 2, in which the advance mechanism has made a first stroke towards the front; FIG. 4 is a view similar to FIG. 2, in which the advance mechanism has made a second stroke towards the front; Figure 5 is a view similar to Figure 2, in which-, the advance mechanism has made a backward stroke 1 rearward; Figure 6 enlarged in perspective of an element of the mechanical pencil shown in Figure 1; - Figure 7 is a partial view of a half longitudinal section of a mechanical pencil according to, a second embodiment of the invention and in which the advance mechanism is in the rest position; Figure 8 is a view similar to Figure 7, in which the advance mechanism has made a back stroke. In the various figures, the same references have been kept to designate identical or similar elements. In Figures 1 to 5 is shown a first embodiment of a mechanical pencil. The mechanical pencil 1 comprises a tubular body 2 which extends along a longitudinal axis X between a front end 2a and a rear end 2b. The body 2 is formed of a tube 3 and a tip 4 arranged at the front end of the body 2. The tip 4 has at its front end an opening through which a lead guide tip 5 which is freely mounted sliding in a bore 4a of the tip 4. The guide tip 5 accompanies the exit of the mine 6 to avoid breakage of the mine. When the wear of the lead reaches the end of the guide tip, the latter touches the paper and makes a backward movement, which releases the end of the lead and allows writing to continue. A side button 7 is mounted through a rectangular window 8 formed in the radial wall of the tubular body 2 and extending along the longitudinal axis X. The side button 7 has an actuation surface 9 oriented radially towards the outside. The side button 7 comprises a first pair of cams 11 arranged opposite the face of one actuator 9 to the front end of the side button having a cross section U. The rear end 7b of the side switch section transverse, also in U, has a second pair of cams 12, analogously to one front end. It will be noted that the first pair of cams 11 is spaced from the second pair of cams 12 by a significant distance measured along the axis X, which is close to the longitudinal length of the actuation face 9 of the side button 7. The part of the side button 7 located inside the body 2 comprises lugs, and in particular a lug 16 which projects towards the rear end 2b of the body 2, which cooperate with the inner periphery of the window 8 and thus prevent the exit complete with the side button 7 of the tubular body 2. Inside the tubular body 2 is arranged a feed mechanism which comprises a movable member 20, a clamp 30, a bush 40, a clamping ring 18 and a compression spring 19 disposed between the movable member 20 and the sleeve 40. The rear end 20b of the mobile organ is equipped with an element 46 projecting through the rear end 2b of the body. The element 46 comprises a tubular part, a clip and a cylindrical recess in which is mounted an eraser 47. The element 46 and the eraser 47 form a rear button which makes it possible to move the movable member 20 forward. L movable member 20 is slidably mounted along the longitudinal axis X in the tubular body 2. In the embodiment shown, the movable member 20 comprises a front part 21 which forms the front end 20a of the movable member and a main part 22 fixed to the front part 21. The main part 22 comprises a first portion located on the side of the front end 20a of the movable member, which will be detailed below, and a hollow rear portion 22b which forms a reservoir of mines. But it is perfectly possible that the mine reservoir is formed by an independent piece fixed to the movable member 20. The front piece 21 of the movable member has a recess oriented towards the front end 2a of the body, the bottom 21a of which forms a bearing surface for the spring 19. The portion front of the main part 22 of the movable member 20 has a first pair of identical ramps 23 arranged on the side of the front end 20a of the movable member. The first ramps 23 are located on either side of a central duct 24 allowing the passage of the mines from the reservoir 22b towards the clamp 30. Each first ramp 23 has a rectilinear surface inclined relative to the longitudinal axis X, oriented towards the rear of the body 2. Thus, when a pressure is exerted on the side button 7 from the rest position shown in FIGS. 1 and 2, the first pair of cams 11 cooperates with the first pair of ramps 23 and causes a displacement towards the front end 2a of the movable member 20. A bearing 25 parallel to the longitudinal axis X is formed on the face of the movable member 20 opposite the side button 7. The bearing 25 s 'extends on either side of the conduit 24 and is positioned longitudinally so that the second pair of cams 12 of the side button 7 can bear on the latter when the side button is in the rest position. A second pair of ramps 26 immediately follows the rear end of the bearing 25. The second ramps 26 are located on either side of the mine tank and are inclined relative to the longitudinal axis in a manner similar to the first ramps 23. The second ramps 26 are spaced longitudinally of the first ramps 23 so that the second pair of cams 12 faces the second ramps 26 when the side button 7 has performed a first tilting movement and is in the position shown in FIG. 3. The body 2 of the mechanical pencil has a flange 27 which extends radially inwards and has a surface 27b parallel to the longitudinal axis X in look from window 8 of the body, against which a protruding boss
28 vient buter à la fin du premier mouvement de basculement du bouton. L'extrémité avant du rebord 27 présente une surface transversale 27a orientée vers l'avant qui forme une butée, dite butée arrière, contre laquelle un épaulement radialement externe 29 de l'organe mobile vient buter. La butée arrière 27a permet ainsi de limiter le recul de l'organe mobile 20. La pince 30 comprend une portion tubulaire 31 et une tête 32 qui coopère de manière connue avec la bague de serrage 18 pour immobiliser la mine 6. Dans les modes de réalisation représentés, la portion tubulaire 31 s'étend depuis une extrémité arrière 31b jusqu'à la tête 32 située du côté de l'extrémité avant28 abuts at the end of the first tilting movement of the button. The front end of the rim 27 has a transverse surface 27a oriented towards the front which forms a stop, known as the rear stop, against which a radially external shoulder 29 of the movable member abuts. The rear stop 27a thus makes it possible to limit the recoil of the movable member 20. The clamp 30 comprises a tubular portion 31 and a head 32 which cooperates in known manner with the clamping ring 18 to immobilize the mine 6. In the modes of embodiment shown, the tubular portion 31 extends from a rear end 31b to the head 32 located on the side of the front end
2a du corps. La portion tubulaire 31 présente depuis son extrémité arrière 31b un premier rebord 33 faisant saillie vers l'extérieur selon une direction radiale perpendiculaire à l'axe longitudinal X, et un deuxième rebord 34 également radialement extérieur. La portion tubulaire 31 de la pince présente une portion tronconique 35 s 'étendant depuis le premier rebord2a of the body. The tubular portion 31 has from its rear end 31b a first flange 33 projecting outwards in a radial direction perpendicular to the longitudinal axis X, and a second flange 34 also radially exterior. The tubular portion 31 of the clamp has a frustoconical portion 35 extending from the first flange
33 jusqu'à l'extrémité arrière 31b, c'est-à-dire que la conicité de la portion 35 est orientée vers l'extrémité arrière de la pince. Ainsi, la pince peut être montée à travers l'ouverture 21c de l'organe mobile 20 par encliquetage. L'extrémité avant de l'organe mobile 20, formée par la pièce avant 21, présente une ouverture 21c à travers laquelle la portion tubulaire 31 de la pince est montée coulissante selon l'axe longitudinal X entre le premier rebord 33 et le deuxième rebord 34. Les premier 33 et deuxième 34 rebords sont espacés longitudinalement de manière à permettre un coulissement longitudinal de la pince 30 par rapport à l'organe mobile 20 sur une longueur déterminée appelée ci-après "course de recul". La douille 40 est montée coulissante dans le corps 2 du porte-mine et elle est également mobile longitudinalement par rapport à la pince 30. Dans le premier mode de réalisation représenté, la douille 40 est une pièce cylindrique qui présente une ouverture centrale 41 à travers laquelle passe la portion tubulaire 31 de la pince, une face avant d'extrémité 42 et une face arrière d'extrémité 43 de forme annulaire plane. Toutefois, la douille 40 pourrait présenter une forme différente, comme par exemple une forme de coupelle . On notera que la face annulaire avant 42 de la douille s'étend sur une distance radiale suffisante pour venir en appui à la fois contre la bague de serrage 18 et contre un rebord radialement interne du corps 2 qui est formé par l'extrémité arrière 4b de la pointe 4. L'extrémité arrière 4b de la pointe forme ainsi une butée solidaire du corps 2, dite butée avant, qui limite le déplacement de la douille 40 vers l'extrémité avant 2a du corps quand la portion périphérique de l'extrémité avant 43 de la bague vient à son contact . Le ressort 19 présente une extrémité avant 19a en appui contre la face arrière 43 de la douille et une extrémité arrière 19b en appui contre la surface d'appui 21a de l'organe mobile, de sorte que le ressort maintient aussi éloigné que possible la douille 40 de l'organe mobile 20. On notera que 1 ' éloignement de ces deux pièces est limité par la pince 30 dont le premier rebord 33 coopère avec l'ouverture 21c de l'organe mobile, et dont la tête 32 limite le déplacement vers l'avant de la bague 18, qui elle-même limite le déplacement vers l'avant de la douille 40. Le mécanisme d'avance forme ainsi un ensemble unitaire- qui peut être pré-assemblé avant son introduction dans le corps 2 du porte-mine par l'extrémité avant du tube 3, ce qui facilite l'assemblage du porte-mine. Il est préférable que la butée avant 4b et la butée arrière 27a du corps 2 soit suffisamment espacées pour permettre un éloignement maximal entre la douille 40 et l'organe mobile 20 lorsque le mécanisme d'avance est en position de repos. En effet, si la distance entre les butées avant 4b et arrière 21a n'est pas suffisante, la douille 40 ne peut pas repousser la bague 18 sur la tête 32 de manière suffisamment avancée pour garantir un serrage maximal de la tête de la pince sur la mine 6. Du fait des tolérances de fabrication des éléments formant le corps 2 et le mécanisme d'avance, il est préférable que les butées avant 4b et arrière 21a soient espacées de manière à ce que le mécanisme d'avance soit monté avec un léger jeu longitudinal dans le corps 2. Toutefois, un tel jeu peut avoir un effet négatif sur la qualité du porte-mine perçue par l'utilisateur, du fait qu'un bruit de cliquetis peut être provoqué par le déplacement du mécanisme d'avance dans le corps 2 lorsque l'utilisateur secoue le porte-mine. Aussi, il est avantageux de prévoir un organe de compensation 50 elastiquement deformable, pour interdire tout déplacement du mécanisme d'avance dans le corps du porte-mine lorsque l'utilisateur n'actionne pas l'un ou 1 'autre des boutons de commande (7, 47) . Dans le mode de réalisation représenté, l'organe de compensation 50 est agencé entre la butée avant 4b du corps et la douille 40, mais il est clair que l'organe de compensation pourrait être agencé entre la butée arrière 27a du corps et la butée complémentaire 29 de l'organe mobile. Comme cela est plus visible sur la figure 6 qui représente la pointe 4 du corps, l'organe de compensation 50 est formé par deux pattes 51 en arc de cercle qui peuvent être elastiquement déformées vers l'extrémité avant 2a. Les extrémités des pattes 51 sont solidaires de la pointe 4, de sorte que les pattes 51 ne forment qu'une seule pièce obtenue par moulage avec la pointe 4. Mais bien entendu, l'organe de compensation 50 pourrait être formé par une pièce indépendante, comme par exemple un ressort de compression de très faible longueur. Toutefois, il est préférable que la raideur de l'organe de compensation 50 soit nettement inférieure à celle du ressort 19 pour que la douille 40 maintienne la bague de serrage 18 le plus en avant possible sur la tête de la pince . Le tube 3 formant le corps du porte-mine comporte deux pions 52 diamétralement opposés, qui s'étendent radialement à l'intérieur du corps 2 entre la douille 40 et l'organe mobile 20. Les pions 52 sont disposés à une distance, mesurée à partir de la face arrière 43 de la douille en position de repos, qui est égale ou légèrement inférieure à la course de recul de la pince 30 par rapport à l'organe mobile 20. Ainsi, le déplacement vers l'arrière de la douille 40 à partir de la reposition de repos, et par conséquent le déplacement de la bague 18, est limité à une valeur au plus égale à la course de recul de la pince, qui est appelée "course effective de recul". Lorsque la pince 30 recule sous l'effet d'une pression ezxcessive exercée par l'utilisateur, le recul de la bague 18 est stoppé en même temps, ou un peu avant, que le deuxième rebord 34 de la pince ne vienne en butée contre 1 ' ouverture 21c de l'organe mobile, comme on peut le voir sur la figure 5. Ceci a pour O 2005/039889 13 effet d'augmenter la force de serrage de la tête 32 de la pince sur la mine 6 de manière directement proportionnelle à la pression exercée par l'utilisateur sur la mine lorsque la course effective de recul de la pince a été atteinte. Ainsi, à partir de cette position de recul maximal, il est quasiment impossible d'obtenir un glissement de la mine dans la tête de la pince. On notera qu ' en 1 ' absence des butées de recul 52 , la force de serrage de la tête de la pince sur la mine serait constante et déterminée par la pression exercée par le ressort 19 sur la douille 40, lorsque le deuxième rebord 34 de la pince vient en butée contre l'organe mobile. Etant donné que la raideur du ressort 19 ne peut pas être trop élevée, l'utilisateur obtiendrait un glissement de la mine dans la pince en exerçant une pression de l'ordre de 15 à 20 newtons sur la mine, ce qui est tout à fait possible. Or, un tel glissement de la mine est désagréable pour l'utilisateur, car il nécessite 1 'actionnement du mécanisme d'avance pour sortir à nouveau la mine. De plus, le glissement de la mine encrasse la tête de la pince avec des particules de graphite, ce qui diminue l'efficacité du serrage de la tête 32 sur la mine. Le ressort 19 est un ressort hélicoïdal de compression réalisé en métal . Ce type de ressort présente l'avantage de pouvoir être comprimé sur une course importante en conservant une raideur constante. De plus, il s'agit d'une pièce standard produite en grande quantité et dont la raideur est parfaitement connue et constante. Toutefois, il est envisageable d'utiliser à la place d'un tel ressort un autre élément élastique, comme par exemple un manchon en matière plastique muni d'ouvertures qui permettent sa compression longitudinale. La force exercée par le ressort doit être suffisamment élevée pour à la fois assurer un serrage de la bague 18 sur la tête 32 qui permette de bloquer O 2005/039889 14 efficacement la mine 6, et ne permettre un recul de la mine que lorsque l'utilisateur exerce une pression réellement excessive, c'est-à-dire nettement supérieure à celle appliquée lors d'une écriture normale. On choisira donc la raideur et la longueur à vide du ressort de manière à ce que la pression exercée sur la douille soit comprise entre 2 et 5 newtons et de préférence 3 newtons, lorsque le mécanisme d'avance est en position de repos . Le ressort 19 sera également choisi en fonction des dimensions du mécanisme d' avance, et notamment de la course de recul, de manière à exercer une pression comprise entre 5 et 10 newtons, et de préférence 8 newtons, lorsque la pince a effectué un déplacement vers l'arrière égal à la course effective de recul de la mine. Le fonctionnement du porte-mine décrit ci-dessus va être explicité à l'aide des figures 2 à 5. En position de repos, représentée à la figure 2, la bague de serrage 18 maintient la tête 32 de la pince serrée sur la mine 6 grâce à l'action du ressort 19. En effet, le ressort 19 exerce, d'une part, une traction vers l'arrière sur la pince, par l'intermédiaire de l'ouverture 21c de l'organe mobile qui est en appui contre le premier rebord 33 de la pince, et d'autre part, une poussée vers l'avant sur la bague de serrage 18, par l'intermédiaire de la douille 40. Dans la position de repos, c'est-à-dire en dehors de tout actionnement du bouton latéral 7 ou bouton arrière formé par l'élément 46 et la gomme 47, la mine 6 est donc maintenue bloquée dans la tête 32 de la pince. En exerçant une pression sur la face d' actionnement33 to the rear end 31b, that is to say that the taper of the portion 35 is oriented towards the rear end of the clamp. Thus, the clamp can be mounted through the opening 21c of the movable member 20 by snap-fastening. The front end of the movable member 20, formed by the front part 21, has an opening 21c through which the tubular portion 31 of the clamp is slidably mounted along the longitudinal axis X between the first flange 33 and the second flange 34. The first 33 and second 34 flanges are spaced apart longitudinally so as to allow longitudinal sliding of the clamp 30 by relative to the movable member 20 over a determined length hereinafter called "recoil stroke". The sleeve 40 is slidably mounted in the body 2 of the mechanical pencil and it is also movable longitudinally relative to the clamp 30. In the first embodiment shown, the sleeve 40 is a cylindrical piece which has a central opening 41 through which passes the tubular portion 31 of the clamp, a front end face 42 and a rear end face 43 of planar annular shape. However, the socket 40 could have a different shape, such as for example a cup shape. It will be noted that the front annular face 42 of the sleeve extends over a radial distance sufficient to come to bear both against the clamping ring 18 and against a radially internal rim of the body 2 which is formed by the rear end 4b of the tip 4. The rear end 4b of the tip thus forms a stop integral with the body 2, called the front stop, which limits the displacement of the bush 40 towards the front end 2a of the body when the peripheral portion of the end before 43 of the ring comes into contact. The spring 19 has a front end 19a bearing against the rear face 43 of the bushing and a rear end 19b bearing against the bearing surface 21a of the movable member, so that the spring keeps the bushing as far apart as possible 40 of the movable member 20. It will be noted that the distance between these two parts is limited by the clamp 30 whose first flange 33 cooperates with the opening 21c of the movable member, and the head 32 of which limits the forward movement of the ring 18, which itself limits the forward movement of the bush 40. The advance mechanism forms thus a unitary assembly which can be pre-assembled before its introduction into the body 2 of the mechanical pencil by the front end of the tube 3, which facilitates the assembly of the mechanical pencil. It is preferable that the front stop 4b and the rear stop 27a of the body 2 be sufficiently spaced to allow maximum distance between the bush 40 and the movable member 20 when the advance mechanism is in the rest position. In fact, if the distance between the front 4b and rear 21a stops is not sufficient, the bush 40 cannot push the ring 18 on the head 32 sufficiently advanced to guarantee maximum clamping of the clamp head on the lead 6. Because of the manufacturing tolerances of the elements forming the body 2 and the advance mechanism, it is preferable that the front stops 4b and rear 21a are spaced so that the advance mechanism is mounted with a slight longitudinal play in the body 2. However, such play can have a negative effect on the quality of the mechanical pencil perceived by the user, since a clicking noise can be caused by the movement of the advance mechanism. in body 2 when the user shakes the mechanical pencil. Also, it is advantageous to provide an elastically deformable compensating member 50, to prevent any movement of the advance mechanism in the body of the mechanical pencil when the user does not actuate one or the other of the control buttons. (7, 47). In the embodiment shown, the compensation member 50 is arranged between the front stop 4b of the body and the sleeve 40, but it is clear that the compensation member could be arranged between the rear stop 27a of the body and the complementary stop 29 of the movable member. As is more visible in Figure 6 which shows the tip 4 of the body, the compensating member 50 is formed by two legs 51 in an arc which can be elastically deformed towards the front end 2a. The ends of the legs 51 are integral with the tip 4, so that the legs 51 form only one piece obtained by molding with the tip 4. But of course, the compensation member 50 could be formed by an independent piece , such as a very short compression spring. However, it is preferable that the stiffness of the compensating member 50 is significantly less than that of the spring 19 so that the bush 40 maintains the clamping ring 18 as far forward as possible on the head of the clamp. The tube 3 forming the body of the mechanical pencil comprises two diametrically opposite pins 52, which extend radially inside the body 2 between the sleeve 40 and the movable member 20. The pins 52 are arranged at a distance, measured from the rear face 43 of the sleeve in the rest position, which is equal to or slightly less than the recoil stroke of the clamp 30 relative to the movable member 20. Thus, the rearward movement of the sleeve 40 from the rest position, and therefore the displacement of the ring 18, is limited to a value at most equal to the recoil stroke of the clamp, which is called "effective recoil stroke". When the clamp 30 moves back under the effect of an ezxcessive pressure exerted by the user, the recoil of the ring 18 is stopped at the same time, or a little before, that the second rim 34 of the clamp comes into abutment against 1 opening 21c of the movable member, as can be seen in Figure 5. This has the O 2005/039889 13 effect of increasing the clamping force of the pliers head 32 on the mine 6 in direct proportion to the pressure exerted by the user on the mine when the effective recoil stroke of the pliers has been reached. Thus, from this position of maximum recoil, it is almost impossible to obtain a sliding of the mine in the head of the pliers. It will be noted that in the absence of the recoil stops 52, the clamping force of the head of the pliers on the lead would be constant and determined by the pressure exerted by the spring 19 on the sleeve 40, when the second flange 34 of the clamp abuts against the movable member. Since the stiffness of the spring 19 cannot be too high, the user would obtain a sliding of the mine in the clamp by exerting a pressure of the order of 15 to 20 newtons on the mine, which is completely possible. However, such a sliding of the mine is unpleasant for the user, because it requires one actuation of the advance mechanism to again exit the mine. In addition, the sliding of the lead fouls the head of the pliers with graphite particles, which reduces the effectiveness of the clamping of the head 32 on the lead. The spring 19 is a helical compression spring made of metal. This type of spring has the advantage of being able to be compressed over a large stroke while maintaining a constant stiffness. In addition, it is a standard part produced in large quantities and whose stiffness is perfectly known and constant. However, it is conceivable to use instead of such a spring another elastic element, such as for example a plastic sleeve provided with openings which allow its longitudinal compression. The force exerted by the spring must be high enough to both ensure a tightening of the ring 18 on the head 32 which allows to block O 2005/039889 14 effectively lead 6, and allow a retreat of the mine only when the user exerts a really excessive pressure, ie clearly higher than that applied during a normal writing. We therefore choose the stiffness and the empty length of the spring so that the pressure exerted on the sleeve is between 2 and 5 newtons and preferably 3 newtons, when the advance mechanism is in the rest position. The spring 19 will also be chosen as a function of the dimensions of the advance mechanism, and in particular of the recoil stroke, so as to exert a pressure of between 5 and 10 newtons, and preferably 8 newtons, when the clamp has moved backward equal to the effective mine recoil stroke. The operation of the mechanical pencil described above will be explained using FIGS. 2 to 5. In the rest position, shown in FIG. 2, the clamping ring 18 maintains the head 32 of the pliers tightened on the lead 6 thanks to the action of the spring 19. In fact, the spring 19 exerts, on the one hand, a rearward pull on the clamp, through the opening 21c of the movable member which is in support against the first flange 33 of the clamp, and on the other hand, a push forward on the clamping ring 18, via the sleeve 40. In the rest position, that is to say say outside of any actuation of the side button 7 or rear button formed by the element 46 and the rubber 47, the lead 6 is therefore kept blocked in the head 32 of the pliers. By exerting pressure on the actuating face
9 du bouton latéral 7, on obtient un premier déplacement vers l'avant de l'organe mobile 20 jusqu'à une position représentée à la figure 3 , par coopération de la première paire de cames 11 du bouton sur la première paire de rampes 23 de l'organe mobile, la deuxième paire de cames 12 restant en appui sur le pallier 25. Au cours de ce premier déplacement, on peut distinguer deux courses de l'organe mobile. Une première course d'environ 2 mm, pendant laquelle l'ouverture 21c de l'organe mobile coulisse le long de la portion tubulaire de la pince depuis le premier rebord 33 jusqu'au deuxième rebord 34, la pince 30 restant immobile lors de cette première course. Puis une deuxième course, dite course d'avance, pendant laquelle l'ouverture 21c de l'organe mobile est en butée contre le deuxième rebord 34 et la pince 30 effectue un déplacement vers l'avant. Pendant cette deuxième course, la bague de serrage 18 accompagne le mouvement de la tête 32 de la pince et par conséquent la mine est déplacée d'une valeur correspondante. On notera qu'au cours de cette deuxième course, la pointe guide-mine 5 reste immobile dans l'alésage 4a de la pointe, du fait d'une force de friction entre la pointe guid -mine 5 et la pointe 4 plus importante que la force de friction entre la pointe guide-mine 5 et la mine 6. Ainsi, après le premier déplacement de l'organe mobile et comme on le voit sur la figure 3, la mine 6 dépasse de l'extrémité avant de la pointe guide-mine '5' d'une valeur égale à la deuxième course, d'où son appellation de course d'avance. Dans le mode de réalisation représenté, cette course d'avance est sensiblement égale à un millimètre, c'est-à-dire environ la moitié de la course de recul . Après ce premier déplacement de l'organe mobile 20, il est possible de commander un deuxième déplacement supplémentaire de celui-ci, afin d'obtenir une sortie complète de la pointe guide-mine 5. Ce deuxième déplacement peut être obtenu en continuant d'exercer une pression sur le bouton latéral 7, ce qui entraîne un glissement de la deuxième paire de cames 12 du bouton le long de la deuxième paire de rampes 26 de l'organe mobile jusqu'à une position représentée à la figure . Au cours de ce deuxième déplacement de l'organe mobile 20, la tête 32 de la pince n'enserre plus la mine 6 du fait de la retenue de la bague 18 par un épaulement 4c de la pointe 4 formé à l'extrémité arrière de l'alésage 4a. On notera que la bague 18 effectue même un mouvement de recul dû à l'élasticité de la tête 32. Par contre, la tête 32 de la pince vient en appui contre l'extrémité arrière de la pointe guide-mine 5, ce qui entraîne la sortie de celle- ci accompagnée de la mine 6. En effet, même si la tête de la pince n'enserre plus la mine 6, celle-ci avance avec la pointe guide-mine 5 du fait de la force de friction existant entre la pointe guide-mine et la mine. A partir de la position représentée à la figure 4, si l'utilisateur relâche la pression sur le bouton latéral 7, le ressort 19 repousse vers l'arrière l'organe mobile 20, ce qui se traduit par un retour du bouton latéral en position de repos du fait de l'action des première 23 et deuxième 26 paires de rampes sur les première 11 et deuxième 12 paires de cames . Au cours de ce mouvement vers 1 ' arrière de 1 ' organe mobile, la pince 30 effectue aussi un mouvement vers l'arrière, mais la tête 32 reste ouverte sur quasiment toute la longueur de ce mouvement et la mine 6 n'effectue quasiment aucun mouvement de recul, de sorte que la pointe guide-mine 5 reste dans la position sortie. A la fin de ce mouvement vers l'arrière, l'ensemble du mécanisme d'avance revient en position de repos, comme représenté sur la figure 2, et la tête 32 de la pince immobilise à nouveau la mine 6, mais la mine et la pointe guide-mine 5 restent sorties comme représenté à la figure 4, de sorte que le porte-mine est prêt à être utilisé. L'avance de la mine décrite ci-dessus est obtenue en actionnant le bouton latéral 7, mais bien entendu, 1 ' actionnement du bouton arrière entraînerait une avance similaire de la mine. Si au cours de l'écriture, l'utilisateur exerce une pression excessive sur la mine 6 qui est immobilisée par la tête 32 de la pince, la mine et la pince 30 reculent vers l'extrémité arrière du stylo grâce à la mobilité longitudinale de la pince par rapport à l'organe mobile 20. Au cours de ce mouvement de recul, la tête 32 de la pince entraîne vers l'arrière la bague de serrage 18 et la douille 40, ce qui comprime le ressort 19. Par conséquent, la résistance au mouvement vers l'arrière de la mine augmente graduellement au cours du mouvement de recul, jusqu'à être maximum pour la position représentée à la figure 5. Ceci confère au mécanisme d'avance un effet de suspension. On notera que l'organe mobile 20 reste immobile pendant le recul de la mine qui n'a, par conséquent, pas d'effet sur les boutons de commande. En l'absence de butée de recul 52, la course effective de recul de la mine est égal à la course de recul de la pince par rapport à l'organe mobile, mais la force de serrage de la pince sur la mine n'augmente plus lorsque le deuxième rebord 34 vient en butée contre l'ouverture 21c de 1 * organe mobile . En présence d'une butée de recul 52, le recul effectif de la mine est de préférence limité à une valeur légèrement inférieure à la course de recul. Toutefois, lorsque la mine a effectué sa course de recul effective, la force de serrage de la tête 32 de la pince sur la mine augmente de manière importante car la bague 18 est alors immobilisée. Ceci évite un glissement de la mine dans la tête 32 de la pince. Si l'utilisateur diminue la pression exercée sur la mine, celle-ci revient de manière automatique dans sa position initiale grâce à l'action du ressort 19 qui repousse la tête 32 de la pince vers l'avant, et le portemine est prêt à être utilisé. Aux figures 7 et 8, est représenté un deuxième mode de réalisation d'un porte-mine selon l'invention. Le corps tubulaire 2 est également formé d'un tube 3 et une pointe 4, toutefois, la pointe 4 ne comporte pas de pointe guide- mine . Le mécanisme d'avance comporte, comme pour le premier mode de réalisation, un organe mobile 20, une pince 30, une bague de serrage 18, une douille 40 et un ressort 19. Pour ce mode de réalisation, le mécanisme d'avance est commandé uniquement par un bouton arrière non représenté sur les figures 7 et 8. L'organe mobile 20 est formé d'une seule pièce avant 21 qui présente une face d'appui 21a tronconique, mais globalement orientée vers l'avant, et contre laquelle prend appui l'extrémité arrière 19b du ressort. La pièce 21 de l'organe mobile présente à son extrémité avant 20a une ouverture 21c à travers laquelle est montée mobile une pince 30 tout à fait similaire à la pince du premier mode de réalisation, de sorte que la portion tubulaire 31 de la pince coulisse dans l'ouverture 21c entre un premier rebord 33 et un deuxième rebord 34 sur une course déterminée dite' de recul . Dans ce deuxième mode de réalisation, l'organe mobile 20 présente un ergot 53 qui fait saillie vers 1 ' extérieur dans une fenêtre 54 s ' étendant longitudinalement dans le tube 3 entre une extrémité avant 54a et une extrémité arrière 54b. L'extrémité arrière 54b de la fenêtre 54 forme une butée arrière du corps qui coopère avec une butée complémentaire de l'organe mobile formé par l'ergot 53, de manière à limiter le déplacement vers l'arrière de l'organe mobile 20. La douille 40 est formée d'une rondelle légèrement conique dont le déplacement vers l'avant est limité par une butée 3a formée par un rebord radialement interne du tube 3, qui présente une première face 55 globalement orientée vers l'arrière du corps. La douille de serrage 18 de ce deuxième mode de réalisation présente un épaulement 18a radialement extérieur et le rebord radialement intérieur 3a du tube présente une face 56 orientée vers l'extrémité avant 2a du corps. La face 56 forme une butée de recul adaptée pour limiter le recul vers l'arrière de la bague de serrage 18. Tout comme pour le premier mode de réalisation, la butée arrière 54b et la butée avant 55 du corps 2 doivent être suffisamment espacées longitudinalement, afin que le mécanisme d'avance immobilise fermement la mine 6 lorsqu'il est dans la position de repos représentée à la figure 7, c'est-à-dire que la douille 40 doit repousser suffisamment la bague de serrage 18 vers l'avant pour que la tête 32 de la pince enserre la mine. L'avance de la mine 6 est commandée par une pression sur le bouton arrière du porte-mine, ce qui provoque un déplacement vers l'avant de l'organe mobile 20 au cours duquel l'ouverture 21c vient en butée contre le deuxième rebord 34 de la pince, puis entraîne un déplacement vers l'avant de la pince jusqu'à ce que la bague de serrage 18 bute contre un rebord 4c de la pointe et provoque l'ouverture de la tête 32 de la pince. Le recul de la pince en position ouverte est ensuite assuré par le ressort 19. L'avance de la mine, dans ce deuxième mode de réalisation, est donc tout à fait similaire à celle du premier mode, bien que la pointe 4 ne comporte pas de pointe guide-mine. Lorsque l'utilisateur exerce une pression excessive sur l'extrémité de la mine 6, la pince 30 recule vers l'arrière en coulissant dans l'ouverture 21c de l'organe mobile et en comprimant le ressort 19. Au cours du mouvement de recul de la pince, l'organe mobile 20 demeure en butée contre la butée arrière 54b du corps. Lorsque la mine a reculé jusqu'à la position représentée à la figure 8, l' épaulement 18a de la bague vient contre la butée de recul 56 du corps, ce qui augmente le serrage de la bague 18 sur la tête de la pince 32 et rend ainsi très difficile un glissement de la mine 6 dans la tête 32. Comme on peut le voir sur la figure 8, le deuxième rebord 34 de la pince n'est pas en contact avec l'ouverture 21c de l'organe mobile lorsque la pince est en position de recul maximum. Par conséquent, pour' ce mode de réalisation, la course effective de recul de la mine 6 est inférieure à la course de recul de la pince 30 par rapport à l'organe mobile . Tout comme pour le premier mode de réalisation, il est possible d'obtenir une course de recul effective sensiblement égale au double de la course d'avance de la mine. Il est également parfaitement possible de choisir un ressort adapté pour exercer sur la douille 40 des pressions sensiblement égales à celles exercées dans le premier mode de réalisation. Bien entendu, les deux modes de réalisation décrits précédemment ne sont pas limitatifs, il est notamment possible de combiner différentes caractéristiques des premier et deuxième modes de réalisation. 9 of the side button 7, a first forward movement of the movable member 20 is obtained to a position shown in FIG. 3, by cooperation of the first pair of cams 11 of the button on the first pair of ramps 23 of the movable member, the second pair of cams 12 remaining supported on the bearing 25. During this first movement, one can distinguish two races of the movable member. A first stroke of approximately 2 mm, during which the opening 21c of the movable member slides along the tubular portion of the clamp from the first flange 33 to the second flange 34, the clamp 30 remaining stationary during this first race. Then a second stroke, called the advance stroke, during which the opening 21c of the movable member is in abutment against the second flange 34 and the clamp 30 moves forward. During this second stroke, the clamping ring 18 accompanies the movement of the head 32 of the pliers and consequently the mine is displaced by a corresponding value. It will be noted that during this second stroke, the guide tip 5 remains stationary in the bore 4a of the tip, due to a friction force between the guide tip-mine 5 and the tip 4 greater than the friction force between the guide tip 5 and the lead 6. Thus, after the first movement of the movable member and as seen in FIG. 3, the lead 6 protrudes from the front end of the guide tip -mine ' 5' of a value equal to the second race, hence its name of advance race. In the embodiment shown, this advance stroke is substantially equal to one millimeter, that is to say approximately half of the reverse stroke. After this first movement of the movable member 20, it is possible to order a second additional movement of the latter, in order to obtain a complete exit from the lead guide tip 5. This second movement can be obtained by continuing to press the side button 7, causing the second pair of cams to slide 12 of the button along the second pair of ramps 26 of the movable member to a position shown in the figure. During this second movement of the movable member 20, the head 32 of the pliers no longer encloses the mine 6 due to the retention of the ring 18 by a shoulder 4c of the tip 4 formed at the rear end of bore 4a. It will be noted that the ring 18 even performs a backward movement due to the elasticity of the head 32. On the other hand, the head 32 of the pliers comes to bear against the rear end of the guide tip 5, which causes the output of the latter accompanied by the mine 6. In fact, even if the pliers head no longer encloses the mine 6, the latter advances with the mine guide tip 5 due to the friction force existing between the mine guide tip and the mine. From the position shown in Figure 4, if the user releases the pressure on the side button 7, the spring 19 pushes the movable member 20 backwards, which results in a return of the side button to the position due to the action of the first 23 and second 26 pairs of ramps on the first 11 and second 12 pairs of cams. During this movement towards the rear of the movable member, the clamp 30 also performs a movement towards the rear, but the head 32 remains open over almost the entire length of this movement and the lead 6 makes almost no movement. backward movement, so that the guide tip 5 remains in the extended position. At the end of this rearward movement, the entire advancing mechanism returns to the rest position, as shown in FIG. 2, and the head 32 of the pliers again immobilizes the mine 6, but the mine and the guide tip 5 remains out as shown in Figure 4, so that the mechanical pencil is ready to be used. The advance of the mine described above is obtained by actuating the side button 7, but of course, actuation of the rear button would cause a similar advance of the mine. If during writing, the user exerts excessive pressure on the lead 6 which is immobilized by the head 32 of the forceps, the lead and the forceps 30 move back towards the rear end of the pen thanks to the longitudinal mobility of the clamp relative to the movable member 20. During this recoil movement, the head 32 of the clamp draws back the clamping ring 18 and the bush 40, which compresses the spring 19. Consequently, the resistance to the rearward movement of the mine gradually increases during the recoil movement, until it is maximum for the position shown in FIG. 5. This gives the advance mechanism a suspension effect. Note that the movable member 20 remains stationary during the retraction of the mine which therefore has no effect on the control buttons. In the absence of a recoil stop 52, the effective recoil stroke of the mine is equal to the recoil stroke of the clamp relative to the movable member, but the clamping force of the clamp on the mine does not increase more when the second rim 34 abuts against the opening 21c of the movable member. In the presence of a recoil stop 52, the effective recoil of the mine is preferably limited to a value slightly less than the recoil stroke. However, when the mine has made its effective recoil stroke, the clamping force of the head 32 of the pliers on the mine increases significantly because the ring 18 is then immobilized. This avoids the mine sliding in the head 32 of the pliers. If the user reduces the pressure exerted on the mine, it returns automatically to its initial position thanks to the action of the spring 19 which pushes the head 32 of the pliers forward, and the mechanical pencil is ready to be used. In Figures 7 and 8, there is shown a second embodiment of a mechanical pencil according to the invention. The tubular body 2 is also formed of a tube 3 and a tip 4, however, the tip 4 does not have a guide tip. The advance mechanism comprises, as for the first embodiment, a movable member 20, a clamp 30, a clamping ring 18, a bush 40 and a spring 19. For this embodiment, the advance mechanism is controlled only by a rear button not shown in Figures 7 and 8. The movable member 20 is formed of a single front piece 21 which has a frustoconical bearing face 21a, but generally oriented towards the front, and against which is supported on the rear end 19b of the spring. The part 21 of the movable member has at its front end 20a an opening 21c through which is movably mounted a clamp 30 quite similar to the clamp of the first embodiment, so that the tubular portion 31 of the clamp slides in the opening 21c between a first flange 33 and a second flange 34 on a determined stroke called 'recoil'. In this second embodiment, the movable member 20 has a lug 53 which projects outwards in a window 54 extending longitudinally in the tube 3 between a front end 54a and a rear end 54b. The rear end 54b of the window 54 forms a rear stop of the body which cooperates with a stop complementary to the movable member formed by the lug 53, so as to limit the rearward movement of the movable member 20. The sleeve 40 is formed of a slightly conical washer whose movement towards the front is limited by a stop 3a formed by a radially internal rim of the tube 3, which has a first face 55 generally oriented towards the rear of the body. The clamping sleeve 18 of this second embodiment has a radially outer shoulder 18a and the radially inner rim 3a of the tube has a face 56 oriented towards the front end 2a of the body. The face 56 forms a recoil stop adapted to limit the backward recoil of the clamping ring 18. Just as for the first embodiment, the rear stop 54b and the front stop 55 of the body 2 must be sufficiently spaced longitudinally , so that the advance mechanism firmly immobilizes the lead 6 when it is in the rest position shown in FIG. 7, that is to say that the sleeve 40 must push the clamping ring 18 sufficiently towards the before so that the head 32 of the pliers grips the mine. The advance of the pencil 6 is controlled by pressing the rear button of the mechanical pencil, which causes the movable member 20 to move forwards, during which the opening 21c abuts against the second edge 34 of the pliers, then causes the pliers to move forward until the clamping ring 18 abuts against a rim 4c of the point and causes the head 32 of the pliers to open. The retraction of the clamp in the open position is then ensured by the spring 19. The advance of the mine, in this second embodiment, is therefore quite similar to that of the first mode, although the tip 4 does not include advanced mine guide. When the user exerts excessive pressure on the end of the lead 6, the clamp 30 moves backwards by sliding in the opening 21c of the movable member and compressing the spring 19. During the recoil movement of the clamp, the movable member 20 remains abutted against the rear stop 54b of the body. When the mine has retreated to the position shown in FIG. 8, the shoulder 18a of the ring comes against the recoil stop 56 of the body, which increases the tightening of the ring 18 on the head of the pliers 32 and This makes it very difficult for the lead 6 to slide in the head 32. As can be seen in FIG. 8, the second rim 34 of the clamp is not in contact with the opening 21c of the movable member when the clamp is in the maximum recoil position. Therefore, for 'this embodiment, the effective stroke of reversing the lead 6 is smaller than the backward stroke of the gripper 30 relative to the movable member. As with the first embodiment, it is possible to obtain an effective recoil stroke substantially equal to twice the advance stroke of the mine. It is also perfectly possible to choose a spring suitable for exerting on the sleeve 40 pressures substantially equal to those exerted in the first embodiment. Of course, the two embodiments described above are not limiting, it is in particular possible to combine different characteristics of the first and second embodiments.

Claims

REVENDICATIONS
1. Porte-mine comprenant un corps tubulaire (2) s ' étendant selon un axe longitudinal (X) entre une extrémité arrière et une extrémité avant (2a) munie d'une ouverture à travers laquelle une mine (6) est susceptible de sortir, et un mécanisme d'avance de la mine agencé dans le corps tubulaire, qui comporte : un organe mobile longitudinalement (20) et présentant une surface d'appui (21a) orientée vers 1 ' avant ; une pince (30) présentant une portion tubulaire (31) reliée à l'organe mobile, et une tête (32) susceptible d'être serrée sur la mine ; - une bague de serrage (18) mobile longitudinalement par rapport à la pince et au corps tubulaire, qui est adaptée pour coopérer avec la tête de la pince ; un élément élastique (19) présentant une extrémité avant et une extrémité arrière (19b) en appui contre la surface d'appui de l'organe mobile, ledit élément élastique étant adapté pour solliciter la bague de serrage, (18) contre la tête (32) de la pince lorsque le mécanisme d'avance est en position de repos, caractérise en ce qu'une douille (40) , mobile longitudinalement par rapport à la pince et au corps, est agencée entre la bague de serrage (40) et l'extrémité avant1. Mechanical pencil comprising a tubular body (2) extending along a longitudinal axis (X) between a rear end and a front end (2a) provided with an opening through which a mine (6) is capable of coming out , and a lead advance mechanism arranged in the tubular body, which comprises: a longitudinally movable member (20) and having a bearing surface (21a) oriented towards the front; a clamp (30) having a tubular portion (31) connected to the movable member, and a head (32) capable of being clamped on the lead; - a clamping ring (18) movable longitudinally with respect to the clamp and the tubular body, which is adapted to cooperate with the head of the clamp; an elastic element (19) having a front end and a rear end (19b) bearing against the bearing surface of the movable member, said elastic element being adapted to urge the clamping ring, (18) against the head ( 32) of the clamp when the advance mechanism is in the rest position, characterized in that a bush (40), movable longitudinally relative to the clamp and to the body, is arranged between the clamping ring (40) and front end
(19a) de l'élément élastique, en ce que la pince (30) est mobile longitudinalement par rapport à l'organe mobile (20) sur une course déterminée, dite course de recul, et en ce que le corps (2) présente une butée avant (4b; 55) adaptée pour limiter le déplacement vers l'avant de la douille (40) . (19a) of the elastic element, in that the clamp (30) is movable longitudinally relative to the movable member (20) over a determined stroke, called the recoil stroke, and in that the body (2) has a front stop (4b; 55) adapted to limit the forward movement of the sleeve (40).
2. Porte-mine selon la revendication 1, dans lequel la butée avant (4b; 55) est formée par un rebord radialement intérieur qui coopère avec une portion périphérique de l'extrémité avant de la douille (40). 2. Mechanical pencil according to claim 1, in which the front stop (4b; 55) is formed by a radially inner rim which cooperates with a peripheral portion of the front end of the sleeve (40).
3. Porte-mine selon la revendication 1 ou 2 , dans lequel l'élément élastique (19) est un ressort de compression hélicoïdal. 3. Mechanical pencil according to claim 1 or 2, wherein the elastic element (19) is a helical compression spring.
4. Porte-mine selon l'une quelconque des revendications 1 à 3, dans lequel la portion tubulaire (31) de la pince présente depuis son extrémité arrière un premier et un deuxième rebords (33,34) radialement extérieurs, et dans lequel l'extrémité avant de l'organe mobile présente une ouverture (21c) à travers laquelle la pince (30) coulisse entre les premier et deuxième rebords, lesdits premier et deuxième rebords étant longitudinalement espacés pour limiter ce coulissement de la pince (30) à une valeur égale à la course de recul. 4. Mechanical pencil according to any one of claims 1 to 3, in which the tubular portion (31) of the clamp has from its rear end a first and a second flange (33,34) radially external, and in which the the front end of the movable member has an opening (21c) through which the clamp (30) slides between the first and second edges, said first and second edges being longitudinally spaced to limit this sliding of the clamp (30) value equal to the recoil stroke.
5. Porte-mine selon la revendication 4, dans lequel la portion tubulaire (31) de la pince présente une portion tronconique (35) s 'étendant depuis le premier rebord (33) jusqu'à l'extrémité arrière (31b) de la pince. 5. Mechanical pencil according to claim 4, wherein the tubular portion (31) of the clamp has a frustoconical portion (35) extending from the first flange (33) to the rear end (31b) of the clamp.
6. Porte-mine selon l'une quelconque des revendications 1 à 5, dans lequel le corps (2) présente une butée arrière (27a; 54b) adaptée pour coopérer avec une butée complémentaire de l'organe mobile et limiter le déplacement vers l'arrière de l'organe mobile (20), la distance longitudinale entre la butée avant (4b; 55) du corps et ladite butée arrière (27a; 54b) étant adaptée pour que la bague de serrage (18) maintienne la pince serrée sous l'action de la douille (40) lorsque le mécanisme d'avance est en position de repos. 6. Mechanical pencil according to any one of claims 1 to 5, wherein the body (2) has a rear stop (27a; 54b) adapted to cooperate with a stop complementary to the movable member and limit the movement towards the 'rear of the movable member (20), the longitudinal distance between the front stop (4b; 55) of the body and said rear stop (27a; 54b) being adapted so that the clamping ring (18) keeps the clamp tight under the action of the sleeve (40) when the advance mechanism is in the rest position.
7. Porte-mine selon la revendication 6, dans lequel la butée arrière (27a) est formée par un rebord radialement intérieur du corps, qui coopère avec un épaulement radialement extérieur (29) de l'organe mobile. 7. Mechanical pencil according to claim 6, wherein the rear stop (27a) is formed by a radially inner rim of the body, which cooperates with a radially outer shoulder (29) of the movable member.
8. Porte-mine selon la revendication 7, dans lequel le corps présente une fenêtre (54) s 'étendant longitudinalement jusqu'à une extrémité arrière, et dans lequel l'organe mobile (20) présente un ergot (53) faisant saillie dans la fenêtre, l'extrémité arrière (54b) de ladite fenêtre formant la butée arrière. 8. Mechanical pencil according to claim 7, in which body has a window (54) extending longitudinally to a rear end, and wherein the movable member (20) has a lug (53) projecting into the window, the rear end (54b) of said window forming the rear stop.
9. Porte-mine selon l'une quelconque des revendications 6 à 8, dans lequel au moins un organe de compensation (50) elastiquement deformable est agencé entre la butée avant du corps et la douille (40) , ou entre la butée arrière du corps et la butée complémentaire de l'organe mobile (20). 9. Mechanical pencil according to any one of claims 6 to 8, in which at least one elastically deformable compensating member (50) is arranged between the front stop of the body and the sleeve (40), or between the rear stop of the body and the complementary stop of the movable member (20).
10. Porte-mine selon la revendication 9, dans lequel l'organe de compensation (50) comprend au moins une patte (51) elastiquement deformable selon une direction longitudinale et venue de matière avec le corps (2) . 10. Mechanical pencil according to claim 9, wherein the compensating member (50) comprises at least one tab (51) elastically deformable in a longitudinal direction and integral with the body (2).
11. Porte-mine selon l'une quelconque des revendications 1 à 10, dans lequel le corps (2) présente une butée de recul (52; 56) adaptée pour limiter le déplacement de la bague de serrage (18) vers l'arrière à partir de la position de repos du mécanisme d'avance, à une valeur au plus égale à la course de recul de la pince (30) . 11. Mechanical pencil according to any one of claims 1 to 10, in which the body (2) has a recoil stop (52; 56) adapted to limit the displacement of the clamping ring (18) towards the rear from the rest position of the advance mechanism, to a value at most equal to the recoil stroke of the clamp (30).
12. Porte-mine selon la revendication 11, dans lequel la butée de recul est formée par au moins un pion (52) solidaire du corps et s 'étendant radialement vers l'intérieur entre la douille (40) et l'organe mobile (20), ledit pion étant adapté pour limiter le déplacement vers l'arrière de la douille. 12. Mechanical pencil according to claim 11, in which the recoil stop is formed by at least one pin (52) integral with the body and extending radially inwards between the sleeve (40) and the movable member ( 20), said pin being adapted to limit the rearward movement of the sleeve.
13. Porte-mine selon la revendication 12, dans lequel la butée de recul est formée par un rebord radialement intérieur (56) du corps, qui est adapté pour coopérer avec un épaulement radialement extérieur (18a) de la bague de serrage. 13. Mechanical pencil according to claim 12, wherein the recoil stop is formed by a radially inner rim (56) of the body, which is adapted to cooperate with a radially outer shoulder (18a) of the clamping ring.
14. Porte-mine selon l'une quelconque des revendications 1 à 13, dans lequel la pince (30) est susceptible d'entraîner la mine (6) vers l'avant sur une course déterminée, dite course d'avance, à partir de la position de repos du mécanisme d'avance, ladite course d'avance étant sensiblement égale à la moitié de la course de recul . 14. Mechanical pencil according to any one of claims 1 to 13, wherein the clamp (30) is capable of driving the mine (6) forward on a determined stroke, called advance stroke, from the rest position of the advance mechanism, said advance stroke being substantially equal to half of the reverse stroke.
15. Porte-mine selon l'une quelconque des revendications 1 à 14, dans lequel l'élément élastique (19) est adapté pour exercer une pression sur la douille (40) comprise entre 2 et 5 newtons, et de préférence 3 newtons, lorsque le mécanisme d'avance est en position de repos, et une pression comprise entre 5 et 10 newtons, et de préférence de 8 newtons, lorsque la pince (30) a effectué un déplacement vers l'arrière sensiblement égal à la course de recul . 15. Mechanical pencil according to any one of claims 1 to 14, in which the elastic element (19) is adapted to exert pressure on the sleeve (40) of between 2 and 5 newtons, and preferably 3 newtons, when the advance mechanism is in the rest position, and a pressure between 5 and 10 newtons, and preferably 8 newtons, when the clamp (30) has moved backwards substantially equal to the recoil stroke .
EP04817287A 2003-10-22 2004-10-18 Mechanical pencil Withdrawn EP1675732A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR0312333A FR2861331B1 (en) 2003-10-22 2003-10-22 DOOR-MINE
PCT/FR2004/002659 WO2005039889A1 (en) 2003-10-22 2004-10-18 Mechanical pencil

Publications (1)

Publication Number Publication Date
EP1675732A1 true EP1675732A1 (en) 2006-07-05

Family

ID=34400694

Family Applications (1)

Application Number Title Priority Date Filing Date
EP04817287A Withdrawn EP1675732A1 (en) 2003-10-22 2004-10-18 Mechanical pencil

Country Status (10)

Country Link
US (1) US20070134046A1 (en)
EP (1) EP1675732A1 (en)
CN (1) CN100503270C (en)
AU (1) AU2004283918A1 (en)
BR (1) BRPI0415642A (en)
CA (1) CA2542879A1 (en)
FR (1) FR2861331B1 (en)
MX (1) MXPA06004495A (en)
TW (1) TW200523135A (en)
WO (1) WO2005039889A1 (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110103874A1 (en) * 2009-10-29 2011-05-05 George Reekie Universal pencil mechanism
JP6079101B2 (en) * 2012-09-28 2017-02-15 ぺんてる株式会社 mechanical pencil
US10272714B2 (en) 2016-12-06 2019-04-30 Sanford L.P. Anti-rotation extendable eraser mechanism
KR20220024201A (en) * 2019-06-20 2022-03-03 가부시키가이샤 파이롯트 코포레이숀 mechanical pencil

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2049965A (en) * 1933-01-31 1936-08-04 Leistenschneider August Lead pencil
US2055316A (en) * 1935-09-26 1936-09-22 Percy A Sharrow Pencil
US3379490A (en) * 1965-11-01 1968-04-23 Schwartzman Gilbert Narrow line applicator
DE2606939C3 (en) * 1976-02-20 1980-10-02 Gebr. Schmidt, Fabrik Fuer Feinmechanik, 7742 St Georgen Writing implement for thin lead
DE2912408A1 (en) * 1978-04-01 1979-10-04 Ancos Co Ltd WRITING DEVICE, IN PARTICULAR MECHANICAL PENCIL
JPS54131426A (en) * 1978-04-01 1979-10-12 Ancos Co Ltd Rotary sliding mechanical pencil
US4371277A (en) * 1980-07-25 1983-02-01 Kotobuki & Co., Ltd. Automatic pencil
JPS58171392U (en) * 1982-05-10 1983-11-16 株式会社寿 Shape pencil
JPS61164790U (en) * 1985-04-02 1986-10-13
US4895467A (en) * 1986-11-25 1990-01-23 Kotobuki & Co., Ltd. Rotary knock type mechanical pencil
JP3323022B2 (en) * 1995-01-19 2002-09-09 株式会社壽 mechanical pencil
WO2001074603A1 (en) * 2000-03-30 2001-10-11 Pentel Kabushiki Kaisha Mechanical pencil
JP3933896B2 (en) * 2001-08-13 2007-06-20 株式会社壽 mechanical pencil

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2005039889A1 *

Also Published As

Publication number Publication date
CA2542879A1 (en) 2005-05-06
FR2861331A1 (en) 2005-04-29
FR2861331B1 (en) 2006-03-03
US20070134046A1 (en) 2007-06-14
CN1871136A (en) 2006-11-29
BRPI0415642A (en) 2006-12-12
AU2004283918A1 (en) 2005-05-06
WO2005039889A1 (en) 2005-05-06
MXPA06004495A (en) 2006-06-27
CN100503270C (en) 2009-06-24
TW200523135A (en) 2005-07-16

Similar Documents

Publication Publication Date Title
EP2809525B1 (en) Retractable tip writing instrument with a protective sleeve
EP1744909A1 (en) Writing instrument with a retractable tip
EP1682207A2 (en) Protected injection syringe device
FR2907371A1 (en) Capless type writing instrument e.g. marker pen, has engagement portions engaged with friction to create bonding force between writing body and sleeve, where one of portions is coaxial to longitudinal axis and its top oriented towards back
FR2742375A1 (en) FIXING PAD SEALING APPARATUS
EP2253248B1 (en) Supporting device for slats comprising an end piece and stiffening means
FR2986466A1 (en) WRITING INSTRUMENT WITH RETRACTABLE POINT PROTECTIVE ELEMENT
FR2606330A1 (en) RETRACTABLE TYPE WRITING INSTRUMENT
EP2234818A2 (en) Writing instrument with eraser protected by a sleeve
WO2006030095A1 (en) Writing instrument
WO2005039888A2 (en) Writing instrument with a lateral button
EP1675732A1 (en) Mechanical pencil
EP3749454B1 (en) System for ejecting tips of sampling pipettes with improved ergonomics
FR2507547A1 (en) MECHANICAL PENCIL IN ADVANCE OF AUTOMATIC MINE
FR2723885A1 (en) MINE CARRIER.
FR2820669A1 (en) HOLDER PISTON
FR2619329A1 (en) AUTOMATIC SHARPENING DEVICE FOR CHAIN SAW
FR2869834A1 (en) MOBILE GUM WRITING INSTRUMENT
FR2865014A1 (en) Drive cable guiding duct maintaining end part for motor vehicle`s gear box, has sleeve that moves on cylindrical section using torsion spring between open position for positioning part in cavity of wall and closed position for locking part
FR2596714A1 (en) BRAKE ASSIST MOTOR
WO1991001893A1 (en) Mechanical letter-opener
FR2465600A1 (en) ROTARY MECHANISM TYPE ROD
BE489183A (en)
FR2816862A1 (en) Coupling device of rotating part to tool comprises base body with coupling head and axial groove in which locking component is located
WO2006027452A1 (en) Hydraulically-controlled writing instrument

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20060410

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE ES FR GB

DAX Request for extension of the european patent (deleted)
RBV Designated contracting states (corrected)

Designated state(s): DE ES FR GB

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Effective date: 20100916