Supporting device for dental instruments

Description

[0001] The present invention relates to support devices for dental instruments, in particular it refers to a device to support and keep in a desired working position a dental instrument, e.g. a dental handpiece like a curing lamp, a intra-oral camera, a suction cannula, etc, which do not require a high placing precision.

[0002] In dentistry, dental chair and dental unit are known, which allow to accommodate a patient while placing at dental staff's disposal the instruments most used during dental treatment, e.g. turbines, micromotors, syringes, curing lamps, scalers, cameras, suction cannulae, etc.

[0003] These dental units comprise one or more supports or instrument holders having housings adapted to receive dental handpieces when not in use by the dentist or the dental assistant.

[0004] These supports are usually in number of two, (called assistant's board and dentist's board), placed at both sides of patient's chair, movably connected to the chair itself or to a dental unit support structure through respective articulated rigid arms, which allow an easy positioning.

[0005] For safety reasons, board housings can be provided with switches, called microswitches, adapted to interrupt power supply and to prevent instrument functioning when instruments are in the housings, and vice versa to allow power supply and therefore functioning, when instruments are extracted from respective housing.

[0006] Moreover, support devices for dental instruments are known, called instrument holders, fastened to a dental unit portion, and configured to keep an instrument in a desired working position, without intervention of dental operators. Typically, these devices save the operator from manually keeping an instrument in a given position, e.g. in patient's oral cavity for a relatively long time. These devices enable the operator not to fatigue and to have hands free for other activities.

[0007] Known support devices comprise articulated structures, typically articulated rigid arms, an end thereof being fastened to one or more parts of a dental unit, e.g. board, support structure, chair and/or headrest; the remaining free end of the device supports the instrument to be used, typically a turbine or micromotor for a dental drill or a burr.

[0008] Said articulated rigid arms comprise a plurality of members suitably shaped and rotatably and/or slidably joined, so as to allow the positioning of instrument in space.

[0009] A disadvantage of these devices is their complexity and bulkiness, which render their construction and assembly difficult and expensive.

[0010] Moreover, the structure complexity requires that dental operator performs quite complicated movements to position the device, and therefore the instrument, in the required position.

[0011] Similarly, when said devices are not used anymore, the disassembly of said devices, fixed for example to dentist's board or to chair headrest, is difficult and slow.

[0012] Support devices for dental instruments, which can be fastened to anatomic parts of patient him/herself (tooth, mandible, head) are known as well. These devices are generally used to guide and provide a precise and accurate reference to so-called dynamic dental instruments, such as drills and/or burrs, and must be disassembled at the end of operation, as they hinder the execution of further operations, e.g. using other instruments.

[0013] These devices, in addition to strongly limiting access to patient's oral cavity, are not suitable for supporting bulky static dental instruments having some weight, such as curing lamps, cameras, etc.

[0014] Furthermore, these support devices are quite uncomfortable and bothersome for the patient.

[0015] US 5547375 discloses a suction device with a suction hose and suction cannula for dental treatment units for the sucking off of the spray mist during dental treatment processes. The suction hose is placed on, or in, a flexible tube, which is movable in three-dimensional manner, so that the suction hose can be brought into the treatment position and can be positioned there without any need for a dental nurse.

[0016] An object of the present invention is to improve known support devices for dental instruments, in particular for dental handpieces.

[0017] Another object is to make a support device having simple and economic construction, allowing to position in rapid, quick and relatively precise way a dental instrument, e.g. a curing lamp.

[0018] A further object is to obtain a device capable of being fastened in a easy, rapid and removable way to a part of the dental unit, in particular a support unit, for instance a dentist's or assistant's board.

[0019] A still further object is to make a support device to which a plurality of dental instruments can be removably connected, in an easy and quick way.

[0020] According to the invention there is provided a support device for dental instruments as defined in claim 1.

[0021] Owing to the invention it is possible to make a support device allowing to support a dental instrument which usually has to be supported by an operator hand, in particular a relatively heavy and bulky dental instrument or handpiece of static type, for instance a curing lamp, a camera, a suction cannula.

[0022] Arm means comprises in fact an elongated, flexible and pliable element of known type, which can be easily bent and positioned according to different working configurations or conformations, to position the supported dental instrument in a plurality of different positions in the space. Moreover, the flexible arm is sufficiently rigid to steadily and firmly support the weight of ordinarily used dental instruments without bending and changing conformation.

[0023] Connecting means is configured so as to allow fastening the device in a housing of a support unit, of known type, of dental unit, in particular a dentist's or assistant's board. In particular, connecting means comprises a connecting element that can be inserted and removably locked in a cylindrical through cavity of the housing, said cavity usually being arranged for receiving support portions or handgrips of dental instruments.

[0024] The connecting element can also be interchanged with a plurality of further connecting elements that differ from one another in shape and dimensions in order to allow the device to be fastened to housings having different shapes and dimensions.

[0025] Hooking means comprises a shaped element provided with two appendixes forming a seat suitable for receiving and holding a dental instrument. A conic shape of the seat and/or a flexibility of opposing appendixes, which can mutually be drawn closer and/or pulled away, allow clamping and locking instruments having different dimensions and shapes. The invention can be better understood and carried into effect with reference to the attached drawings, in which an embodiment of the invention are shown by way of non-limiting example, wherein:

Figure 1 is a schematic perspective view of the support device for dental instruments of the invention;

Figure 2A and 2B are perspective views of the device of Figure 1 in respective working configurations;

Figure 3 is a perspective view of the device of Figure 1 supporting a dental instrument and associated with a support unit of a dental unit;

Figure 4 is a perspective view of the device of Figure 3 in an assembly condition on the support unit;

Figure 5 is an enlarged partial perspective view of the device of Figure 3, showing connecting means of said device and housings of said support unit.

[0026] With reference to Figures 1 to 5, there is illustrated a support device 1 for dental instruments associable to a dental unit.

[0027] Device 1 comprises arm means 2 provided, at a first proximal end 2a with connecting means 3 arranged for connecting the device 1 to dental unit, and, at a second distal end 2b, with hooking means 4 to removably receive and support a dental instrument 50, in particular a dental handpiece.

[0028] Arm means 2 comprises an elongated flexible articulated element, in particular a flexible articulated tube of known type, commonly called flexible gooseneck or swanlike neck and used, for instance, for lamp stems.

[0029] This flexible articulated tube can be for instance of metallic or plastic ring type, having spherical connection portions.

[0030] This flexible and articulated arm can be easily bent and positioned (Figure 2A, 2B) according to different working configurations or conformations to allow hooking means 4, and thus instrument 50 connected thereto, to reach a plurality of positions in space.

[0031] Furthermore, arm 2 is sufficiently rigid to support in a steady way the weight of usually used dental instruments (for example 100-200 g) without bending or changing conformation. Arm 2 is covered with a sheath made of hygienisable material, for instance made of rubber or silicone, which ensures an easier and effective cleaning of the external surface of arm 2. The sheath forms, in fact, a surface lacking interstices and cracks.

[0032] Alternatively, arm 2 can comprise other flexible and articulated stems of known type, provided with an internal core, for example a rigid chain or a helical spring, incorporated in an elastomeric material.

[0033] Connecting means 3 is configured so as to allow removably inserting the device 1 in a housing 21 of a support unit 20, of known type, of dental unit, in particular a dentist's or assistant's board.

[0034] Housing 21 comprises a cylindrical through cavity 22, provided with a longitudinal lateral opening 22a and designed to receive support portions or handgrips of dental instruments, in particular dental handpieces.

[0035] A further cylindrical or conic cavity 24 of greater dimensions is provided at the opening of through cavity 22 in order to facilitate instrument insertion.

[0036] One or more further housings for connecting means 3 can be provided on different portions of dental unit, for example on the headrest or on the chair back, on a lamp post, on a support arm of dentist's board.

[0037] Connecting means comprises a connecting element 3 shaped so as to engage the cavity 22 of housing 21.

[0038] Connecting element 3 comprises a first portion 3a having substantially truncated conical shape and a second portion 3b, interposed between said first portion 3a and the first end 2a of arm 2, having nearly cylindrical shape and a diameter slightly bigger than diameter of cavity 22. The first portion 3a allows to easily insert connecting element 3 into the cavity 22; the second portion 3b, forced with a light interference in said cavity 22, removably blocks the connecting element 3 and therefore the device 1 in an assembly position A (Figure 4).

[0039] Should housing 21 be provided with a switch or operation micro switch 23 of dental instrument 50 associated therewith, connecting.element 3 is shaped so as to avoid activating said switch 23 when it is inserted in the cavity 22. In this way, dental instrument 50 associated with housing 21 can work when mounted on device 1, even if the latter engages housing 21. The further housings provided on other portions of dental unit are not endowed with operation switches because they are not designed to support resting dental instruments.

[0040] For this reason, connecting element 3 is provided with a longitudinal groove 3c, suitably shaped and dimensioned, arranged facing said switch 23 in said assembly condition A.

[0041] Connecting element 3 is interchangeable with a plurality of further connecting elements that differ from one another in shape and dimensions of portions 3a, 3b, so as to allow device 1 to be fastened to housings 21 having different shapes and dimensions.

[0042] For this reason, connecting means 3 is removably connected to the first end 2a of arm 2, for example through threaded joint or through reversible fixed joint.

[0043] Handgrip means 5 is provided at said first end 2a of arm 2, so as to allow an easy grip of device 1 by dental operators. Handgrip means 5 comprises a substantially cylindrical element fastened to said first end 2a and made of metallic material, for example. Handgrip means 5 has dimensions - length and diameter - such as to allow an easy and comfortable manual grip.

[0044] Handgrip means 5 is interposed between said first end 2a of arm 2 and connecting means 3. In this case, connecting element 3 is removably fixed to said handgrip means 5.

[0045] Hooking means 4 comprises a shaped element provided with two opposed appendixes 6, 7, internally shaped so as to realize a seat 8 suitable to receive a portion 50a, for instance a handgrip, of an instrument or handpiece 50.

[0046] Seat 8 has a conical shape having a diameter increasing from second end 2b of arm 2 towards outside, to receive handpieces 50 having different dimensions and shapes.

[0047] Seat 8 can have also..sections having any shape, for instance elliptic or prismatic, having width increasing from second end 2b towards outside.

[0048] Hooking means 4 is made of an elastically yielding material, so that opposing appendixes 6, 7 by extending can grip and lock in seat 8 handgrips 50a having different diameter and even different shape, e.g. elliptic, prismatic, etc. Alternatively, hooking means 4 comprises a C-shaped rigid internal core, to realize opposing appendixes 6, 7, externally covered with a more yielding material, for instance rubber or silicone.

[0049] As illustrated in Figures 3 and 4, in use the support device 1 supports a dental instrument 50, for instance a curing lamp, removably fixed to hooking means 4, the handgrip 50a of said instrument being inserted and removably locked in seat 8.

[0050] At the same time, connecting means 3 is fixed to support unit 20, for example a dentist's board, through the insertion of connecting element in housing 21, in the assembly condition A. Groove 3c provided in connecting element 3 allows to keep disengaged operation switch 23 of instrument 50, which can therefore freely work.

[0051] Flexible, bendable and positionable arm 2 allows to position in space in the desired way an instrument 50 and to maintain it in a steady and relatively precise working position. Support device 1 allows therefore to sustain a plurality of dental instruments, which normally have to be supported by the hand of a dental operator (chair assistant or dentist), in particular relatively heavy and bulky dental instruments or handpieces of static type, such as curing lamps, cameras, suction cannulae.

Claims

1. Support device for dental instruments associable with a dental unit, comprising arm means (2) provided with, at a first end (2a), connecting means (3) to removably connect said device (1) to said dental unit and, at a second end (2b), provided with hooking means (4) to removably receive and support a dental instrument (50), said arm means (2) comprising an elongated flexible element, pliable and positionable so as to steadily position said dental instrument (50) in a plurality of different positions, characterized in that said connecting means (3) is arranged for engaging a housing (21) of a support unit (20) of said dental unit, said housing (21) being arranged for receiving dental instruments.

2. Device according to claim 1, wherein said elongated element (2) comprises a flexible articulated tube, in particular a tube with metallic rings having spherical connecting portions.

3. Device according to claim 1 or 2, wherein said arm means (2) is covered with a sheath made of hygienisable material, in particular rubber or silicone.

4. Device according to any preceding claim, wherein said connecting means (3) is arranged for engaging a further housing provided on a portion of said dental unit, in particular on a headrest, a chair back, a lamp post, a support unit arm.

5. Device according to any preceding claim, wherein said connecting means comprises a connecting element (3) arranged to be inserted and removably locked in a cavity (22) of said housing (21), in an assembly condition (A) of said device (1) on said dental unit (20).

6. Device according to claim 5, wherein said connecting element (3) comprises at least a portion (3a) having substantially truncated conical shape.

7. Device according to claim 6, wherein said connecting element (3) comprises a further portion (3b) having nearly cylindrical shape, interposed between said first portion (3a) and said first end (2a) of said arm means (2).

8. Device according to any one of claims 5 to 7, wherein said connecting means (3) is shaped so as to avoid engaging, in said assembly condition (A), a operation switch (23) provided in said cavity (22) to activate and/or deactivate a dental instrument (50) associated with said housing (21).

9. Device according to claim 8, wherein said connecting element (3) comprises a groove (3c) arranged substantially facing said operation switch (23) in said assembly condition (A).

10. Device according to any preceding claim, comprising handgrip means (5) interposed between said first end (2a) of arm means (2) and said connecting means (3) to allow the grip of said device (1) by an operator.

11. Device according to claim 10, wherein said handgrip means (5) comprises a substantially cylindrical element fixed to said first end (2a).

12. Device according to any preceding claim, wherein said connecting means (3) is removably fixed to said first end (2a) of said arm means (2).

13. Device according to claim 12, as appended to claim 10 or 11, wherein said connecting means (3) is removably fixed to said handgrip means (5).

14. Device according to claim 12 or 13, wherein said connecting means comprises a plurality of interchangeable connecting means (3). ,

15. Device according to any preceding claims, wherein said hooking means (4) comprises a shaped element provided with two opposing appendixes (6, 7), shaped so as to realize a seat (8) suitable to receive a portion (50a) of said dental instrument (50).

16. Device according to claim 15, wherein said hooking means (4) is made of elastically yielding material so that said opposing appendixes (6, 7) can be mutually spaced apart to receive and lock in said seat (8) handpieces (50) having different dimensions and/or shapes.

17. Device according to claim 15, wherein said hooking means (4) comprises a C-shaped rigid core, externally covered with a yielding material, especially rubber or silicone.

18. Device according to any one of claims 15 to 17, wherein said seat (8) has a substantially conical shape.

Ansprüche

1. Haltevorrichtung für zahnärztliche Instrumente, die an eine zahnärztliche Apparatur anschließbar sind, mit Armmitteln (2), die an einem ersten Ende (2a) mit Verbindungsmitteln (3) versehen sind, um die Vorrichtung (1) mit der zahnärztlichen Apparatur abnehmbar zu verbinden, und an einem zweiten Ende (2b) mit Einhängemitteln (4) versehen sind, um ein zahnärztliches Instrument (50) abnehmbar aufzunehmen und zu halten, wobei die Armmittel (2) ein längliches flexibles Element aufweisen, das biegsam und positionierbar ist, um das zahnärztliche Instrument (50) in einer Mehrzahl von verschiedenen Positionen beständig zu positionieren, dadurch gekennzeichnet, dass die Verbindungsmittel (3) dazu ausgelegt sind, mit einem Gehäuse (21) einer Halteapparatur (20) der zahnärztlichen Apparatur in Eingriff gebracht zu werden, wobei das Gehäuse (21) dazu ausgelegt ist, zahnärztliche Instrumente aufzunehmen.

2. Vorrichtung nach Anspruch 1, wobei das längliche Element (2) ein flexibles gelenkiges Rohr, insbesondere ein Rohr mit Metallringen, aufweist, die kugelförmige Verbindungsabschnitte aufweisen.

3. Vorrichtung nach Anspruch 1 oder 2, wobei die Armmittel (2) mit einer Hülle bedeckt sind, die aus einem hygienisierbaren Material gefertigt ist, insbesondere aus Gummi oder Silicon.

4. Vorrichtung nach einem der vorhergehenden Ansprüche, wobei die Verbindungsmittel (3) dazu ausgelegt sind, mit einem weiteren Gehäuse in Eingriff gebracht zu werden, das an einem Abschnitt der zahnärztlichen Apparatur vorgesehen ist, insbesondere an einer Kopfstütze, an einer Rücklehne, an einem Lampenständer, an einem Arm einer Halteapparatur.

5. Vorrichtung nach einem der vorhergehenden Ansprüche, wobei die Verbindungsmittel ein Verbindungselement (3) aufweisen, das dazu ausgelegt ist, in einem an der zahnärztlichen Apparatur (20) montierten Zustand (A) der Vorrichtung (1) in einen Hohlraum (22) des Gehäuses (21) eingesetzt und darin abnehmbar verriegelt zu werden.

6. Vorrichtung nach Anspruch 5, wobei das Verbindungselement (3) zumindest einen Abschnitt (3a) aufweist, der eine im Wesentlichen kegelstumpfförmige Form aufweist.

7. Vorrichtung nach Anspruch 6, wobei das Verbindungselement (3) einen weiteren Abschnitt (3b) aufweist, der eine etwa zylindrische Form aufweist, und der zwischen dem ersten Abschnitt (3a) und dem ersten Ende (2a) der Armmittel (2) angeordnet ist.

8. Vorrichtung nach einem der Ansprüche 5 bis 7, wobei die Verbindungsmittel (3) so geformt sind, dass in dem montierten Zustand (A) ein in Eingriffkommen mit einem Betätigungsschalter (23) vermieden wird, der in dem Hohlraum (22) vorgesehen ist, um ein zahnärztliches Instrument (50), das an das Gehäuse (21) angeschlossen ist, zu aktivieren und/oder zu deaktivieren.

9. Vorrichtung nach Anspruch 8, wobei das Verbindungselement (3) eine Nut (3c) aufweist, die so angeordnet ist, dass sie dem Betätigungsschalter (23) in dem montierten Zustand (A) im Wesentlichen zugewandt ist.

10. Vorrichtung nach einem der vorhergehenden Ansprüche, mit Handgriffmitteln (5), die zwischen dem ersten Ende (2a) der Armmittel (2) und den Verbindungsmitteln (3) angeordnet sind, um das Greifen der Vorrichtung (1) durch eine Bedienungsperson zu ermöglichen.

11. Vorrichtung nach Anspruch 10, wobei die Handgriffmittel (5) ein im Wesentlichen zylindrisches Element aufweisen, das an dem ersten Ende (2a) befestigt ist.

12. Vorrichtung nach einem der vorhergehenden Ansprüche, wobei die Verbindungsmittel (3) abnehmbar an dem ersten Ende (2a) der Armmittel (2) befestigt sind.

13. Vorrichtung nach Anspruch 12, soweit dieser auf Anspruch 10 oder 11 rückbezogen ist, wobei die Verbindungsmittel (3) an den Handgriffmitteln (5) abnehmbar befestigt sind.

14. Vorrichtung nach Anspruch 12 oder 13, wobei die Verbindungsmittel eine Mehrzahl von austauschbaren Verbindungsmitteln (3) aufweisen.

15. Vorrichtung nach einem der vorhergehenden Ansprüche, wobei die Einhängemittel (4) ein geformtes Element aufweisen, das mit zwei gegenüberliegenden Fortsätzen (6, 7) versehen ist, die so geformt sind, dass sie einen Sitz (8) realisieren, der geeignet ist, einen Abschnitt (50a) des zahnärztlichen Instruments (50) aufzunehmen.

16. Vorrichtung nach Anspruch 15, wobei die Einhängemittel (4) aus elastisch nachgiebigem Material gefertigt sind, so dass die gegenüberliegenden Fortsätze (6, 7) voneinander beabstandet werden können, um Handstücke (50) mit unterschiedlichen Abmessungen und/oder Formen aufzunehmen und in dem Sitz (8) zu verriegeln.

17. Vorrichtung nach Anspruch 15, wobei die Einhängemittel (4) einen C-förmigen starren Kern aufweisen, der außenseitig mit einem nachgiebigen Material, insbesondere Gummi oder Silicon, bedeckt ist.

18. Vorrichtung nach einem der Ansprüche 15 bis 17, wobei der Sitz (8) eine im Wesentlichen konische Form aufweist.

Revendications

1. Dispositif de support pour des instruments dentaires associables à une unité dentaire, comprenant des moyens de bras (2) munis, à une première extrémité (2a), de moyens de raccordement (3) destinés à raccorder de manière amovible ledit dispositif (1) à ladite unité dentaire et munis, à une deuxième extrémité (2b), de moyens d'accrochage (4) destinés à recevoir et supporter de manière amovible un instrument dentaire (50), lesdits moyens de bras (2) comprenant un élément allongé flexible, pliable et positionnable de façon à positionner de manière stable ledit instrument dentaire (50) dans une pluralité de positions différentes, caractérisé en ce que lesdits moyens de raccordement (3) sont prévus pour s'engager dans un logement (21) d'une unité de support (20) de ladite unité dentaire, ledit logement (21) étant aménagé pour recevoir des instruments dentaires.

2. Dispositif selon la revendication 1, dans lequel ledit élément allongé (2) comprend un tube articulé flexible, en particulier un tube avec des anneaux métalliques ayant des portions de raccordement sphériques.

3. Dispositif selon la revendication 1 ou 2, dans lequel lesdits moyens de bras (2) sont recouverts d'une gaine faite d'un matériau stérilisable, en particulier de caoutchouc ou de silicone.

4. Dispositif selon l'une quelconque des revendications précédentes, dans lequel lesdits moyens de raccordement (3) sont prévus pour s'engager dans un autre logement ménagé sur une portion de ladite unité dentaire, en particulier sur un appuie-tête, un dossier de fauteuil, un lampadaire, un bras de l'unité de support.

5. Dispositif selon l'une quelconque des revendications précédentes, dans lequel lesdits moyens de raccordement comprennent un élément de raccordement (3) prévu pour être inséré et bloqué temporairement dans une cavité (22) dudit logement (21), dans un état assemblé (A) dudit dispositif (1) sur ladite unité dentaire (20).

6. Dispositif selon la revendication 5, dans lequel ledit élément de raccordement (3) comprend au moins une portion (3a) ayant une forme sensiblement tronconique.

7. Dispositif selon la revendication 6, dans lequel ledit élément de raccordement (3) comprend une autre portion (3b) ayant une forme quasi cylindrique, interposée entre ladite première portion (3a) et ladite première extrémité (2a) desdits moyens de bras (2).

8. Dispositif selon l'une quelconque des revendications 5 à 7, dans lequel lesdits moyens de raccordement (3) sont conformés de manière à éviter d'engager, dans ledit état assemblé (A), un interrupteur de service (23) prévu dans ladite cavité (22) pour activer et/ou désactiver un instrument dentaire (50) associé audit logement (21).

9. Dispositif selon la revendication 8, dans lequel ledit élément de raccordement (3) comprend une rainure (3c) placée sensiblement en vis-à-vis dudit interrupteur de service (23) dans ledit état assemblé (A).

10. Dispositif selon l'une quelconque des revendications précédentes, comprenant des moyens de poignée (5) interposés entre ladite première extrémité (2a) des moyens de bras (2) et lesdits moyens de raccordement (3) pour permettre la prise dudit dispositif (1) par un opérateur.

11. Dispositif selon la revendication 10, dans lequel lesdits moyens de poignée (5) comprennent un élément sensiblement cylindrique fixé à ladite première extrémité (2a).

12. Dispositif selon l'une quelconque des revendications précédentes, dans lequel lesdits moyens de raccordement (3) sont fixés de manière amovible à ladite première extrémité (2a) desdits moyens de bras (2).

13. Dispositif selon la revendication 12, lorsqu'elle est dépendante de la revendication 10 ou 11, dans lequel lesdits moyens de raccordement (3) sont fixés de manière amovible auxdits moyens de poignée (5).

14. Dispositif selon la revendication 12 ou 13, dans lequel lesdits moyens de raccordement comprennent une pluralité de moyens de raccordement interchangeables (3).

15. Dispositif selon l'une quelconque des revendications précédentes, dans lequel lesdits moyens d'accrochage (4) comprennent un élément profilé pourvu de deux appendices en vis-à-vis (6, 7), conformé de manière à réaliser un siège (8) apte à recevoir une portion (50a) dudit instrument dentaire (50).

16. Dispositif selon la revendication 15, dans lequel lesdits moyens d'accrochage (4) sont faits d'un matériau souple de façon que lesdits appendices opposés (6, 7) puissent s'écarter l'un de l'autre pour recevoir et bloquer dans ledit siège (8) des pièces à main (50) de différentes dimensions et/ou formes.

17. Dispositif selon la revendication 15, dans lequel lesdits moyens d'accrochage (4) comprennent un noyau rigide en forme de C, recouvert extérieurement d'un matériau souple, tout particulièrement du caoutchouc ou du silicone.

18. Dispositif selon l'une quelconque des revendications 15 à 17, dans lequel ledit siège (8) possède une forme essentiellement conique.

Drawing