FR2692454A1 - Arm chair on wheels for person with reduced mobility - has quadrilateral bars moved by jack operated by pedal to adjust height of seat and having retractable head rest - Google Patents

Abstract

The armchair (5) has feet (1), mounted on wheels (12). The height of its seat (6) is adjusted by an articulated quadrilateral with a bent lever (20), and a pair of parallel bars (21, 22), articulated on the lever (23, 24). The seat is articulated on an axle (61) at the top of the lever. The quadrilateral is moved by a hydraulic or pneumatic jack (28), operated by a pedal. Its rod is articulated o a bar (26) joined to the lower bar's axle (25) on the chassis (10). The head rest (9) has an extension, held in a recess in the back (7), which pivots backwards on a transversal axle (92). USE - Arm chair with adjustable height seat for person with reduced mobility.

Description

ARMCHAIR FOR PERSONS WITH REDUCED MOBILITY
The present invention relates to an armchair for a person with reduced mobility, that is to say for a person having difficulty in moving and having to be assisted by an assistant. This is particularly the case for the elderly and for people with disabilities of the lower limbs.

 The main objective of the invention is to propose an armchair of new design which brings to the patient (that is to say to the person using the armchair) an increased comfort, the seat being able to be perfectly adapted to the morphology of the patient .

 Another object of the invention is to provide an armchair whose use is convenient both for the patient and for his help.

 Another object of the invention is to provide an improved hygiene chair, which can be easily and completely washed and / or disinfected in existing installations, in particular in the washing and disinfection tunnels with which the centers intended to use the wheelchair, such as hospitals, rehabilitation centers and residential centers for the elderly.

These various results are achieved, in accordance with the invention thanks to the fact that the chair comprises
- a base mounted on wheels
- a seat composed of a seat, a backrest and a headrest, carried by said base
- Adjustment means which make it possible to adjust the height of the seat relative to the base.

Furthermore, according to a certain number of advantageous, but not limiting, characteristics
- Said adjustment means comprise an articulated quadrilateral actuated by a hydraulic or pneumatic control member, for example a pump / jack device
- the chair has a headrest which is retractable by tilting the back of the backrest
- The headrest has the general shape of a "T" whose vertical branch is housed and is articulated inside a cavity of complementary shape formed on the back of the backrest, which allows the complete tilting of the headrest backwards and downwards
- the inclination of the headrest relative to the backrest is adjustable
- the back of the backrest has, at its upper part, two lateral recesses and is provided with a pair of handles arranged opposite these recesses, handle and recess delimiting a cavity with a closed contour for the passage of the fingers
- the inclinations on the one hand of the entire seat with respect to the base and on the other hand of the backrest with respect to the seat are adjustable;
- the armchair is provided with a footstool carried by the base and retractable inside it
- this step has a protrusion on the ground
- the seat, the backrest and the headrest include cushions which are removable, with rapid fixing, for example by a fastening system with gripping fabrics
- These cushions are formed of a plastic film shaped on a flexible synthetic material, their bearing face with the person being devoid of seam (cause of bedsores);
- with the exception of removable cushions, the entire chair is suitable for being washed and / or disinfected in a washing / disinfection tunnel
- The armchair comprises a pair of armrests carried by the seat and movable in height, these armrests being able to be retracted by lowering at the level of the seat.

 Other characteristics and advantages of the invention will appear from the description and the appended drawings which represent preferred embodiments thereof.

On these drawings
- Figures 1 and 2 are general perspective views of the chair, respectively from the side and from the back
- Figure 3 is a schematic sectional view, with partial cutaway, of the chair seen from the side
- Figure 4 is a partial view similar to Figure 3 illustrating the principle of seat height adjustment
- Figure 4A is a detail view of the step, this view being intended to show how the step comes to bear against the ground by means of a protuberance, preventing the tilting towards the front of the chair
- Figure 5 is a cross-sectional view of the backrest, the cutting plane being designated VV in Figure 2
- Figure 6 is a cross-sectional view of a cushion intended to equip the backrest in the variant of Figure 9, the cutting plane being referenced VI-VI in this Figure 9
- Figure 7 is a detail view showing a possible embodiment of mounting a retractable armrest on the chair
- Figure 8 is a schematic view showing a mechanism for locking and adjusting the inclination of the headrest
- Figure 9 is an exploded perspective view showing an embodiment of the main components of the seat, these elements comprising rigid shells of thermoformed plastic material on which can be fixed cushions (the latter being shown seen from the back).

 The chair shown in Figures 1, 2 and 3 comprises a base 1 mounted on four wheels 12, a seat 5 mounted on this base by means of a mechanism 2 with articulated quadrilateral allowing its height adjustment. In fact, there are two articulated quadrilaterals arranged parallel to each other on either side of the vertical plane of symmetry of the chair, these quadrilaterals being articulated on common axes arranged transversely.

 The seat 5 is composed of a seat 6, a backrest 7 and a headrest member 9. The backrest 7 is articulated on the seat by means of a transverse axis 71 while the headrest 9 is articulated on the backrest around a transverse axis 92.

 The base 1 comprises a frame 10 which is extended forwards by an arch in a curved cylindrical tube 100. The front wheels are fixed to the free ends of this arch while the rear wheels are fixed to the ends of a transverse tube 30 integral chassis 10.

 The tube 30 contains actuation means on the one hand of a brake pad for the rear wheels 12, and on the other hand of a device for immobilizing the axis of one of the wheels in a transverse position .

The implementation of this locking means facilitates guiding the chair when it has to be moved in a rectilinear manner, parallel to the longitudinal plane of symmetry of the chair. The braking and locking means of the orientation of the wheels are means known per se and which will not be described here so as not to unnecessarily burden the description and the drawings.

 According to a characteristic of the invention, the control of these means is done using a pair of pedals which are mounted at both ends of the tube 30. To actuate the brake pads, the nursing assistant presses the foot either of these pedals in one direction; to actuate the means for blocking the orientation of one of the wheels, he presses one or the other of the pedals in the other direction. It is noted that the pedals have for this purpose a symmetrical shape and are provided with bearing faces extending both forwards and backwards relative to the tube 30 (see in particular Figure 3).

 These pedals have flat internal faces which seal against the ends of the tube 30, so that water cannot access the mechanism housed in the tube when the chair is washed, for example with a jet of water or inside a washing tunnel.

 Advantageously, the pedals 31 are flexible plastic parts produced by molding, for example PVC (polyvinyl chloride). Their upper face has ridges 310, or other reliefs, preventing the shoe from sliding when the pedal is pressed. Because the material of the pedals 31 is flexible, these pedals act as damping stops acting in the event of a rear impact of the chair, for example against a wall.

 A front step 4 is provided at the front part of the base. It is a platform which, in the use position, extends horizontally at the front of the base, a short distance from the ground. The underside of the platform is provided with a protuberance 41, preferably made of flexible plastic. This pad practically touches the ground. Its function will be explained later, with particular reference to Figure 4A.

 The step 4 is carried by a mechanism, for example an articulated quadrilateral, which allows it to be retracted inside the base. In FIG. 3, the dashboard 4 is shown in dashed lines in its retracted position, referenced 4 ′, retracted inside the arch 100. Advantageously, the retraction is done by deformation of the articulated quadrilateral and passage from a neutral point, the same traction spring ensuring the elastic return of the step in its deployed position or in its retracted position, on the side. and other of this dead center.

 The arrow H has been symbolized in Figure 3 the movement of the step for its retraction.

 The mechanism 2 which makes it possible to raise and lower the seat with respect to the base is composed of an angled lever 20, the upper end of which carries the hinge pin 61 of the seat 6. I1 also comprises a pair of parallel links 21, 22. These links are articulated at their rear end respectively by a transverse axis 23 at the central part of the bent lever 20 and by a transverse axis 24 at the lower end of the lever 20. The front end of the link upper 21 is articulated around a transverse axis 27 in a gusset fixed on the chassis 10. The front end of the lower link 22 is secured to a transverse axis 25 guided in rotation in the chassis 10.A hydraulic control device of known type and commonly used in this type of application, for example a pump / actuator device 28 makes it possible to control the deformation of the mechanism 2. To this end, the device 28 whose actuator body is articulated on the chassis 10, has a control rod whose end is articulated to a rod 26 secured to the axis 25. A control means such as a pedal 280 (see FIG. 1) makes it possible to control the pump device / cylinder 28 in one direction or the other.

 This device 28 could be replaced by a gas locking spring, also well known in this type of application.

 The stability of the seat 5 relative to the mechanism 2 is ensured by a gas locking spring 63, of known type. In Figure 3, this spring is schematically shown by a strong broken line. The spring 63 is interposed between a point 62 of the seat 6 located at the rear of its articulation axis 61 and a point 200 located at the bottom of the lever 20 (between axes 23 and 24). It is easily understood that by actuating the gas spring 63, in the direction of its elongation or its retraction, it is possible to tilt the whole of the seat forwards or backwards relative to the mechanism 2 and consequently by compared to the fixed base 1.

 As already said above, the backrest 7 is itself articulated on the seat 6 around an axis 71. This variable inclination is also advantageously controlled by a gas locking spring 72. The latter is located on the back of the backrest , at the lower part thereof, and is interposed between an upper stop 720 secured to the backrest and a lower stop 60 secured to the seat. It is easy to understand that by varying the length of the gas spring 72, the inclination of the backrest 7 relative to the seat 6 can be modified.

 Advantageously, the inclination of the entire seat 5 (block tilting of the seat, the backrest and the headrest) and the inclination of the backrest (and of the headrest) relative to the 'seat are made by a common control member such as a lever 50 (see Figure 1). This lever can be connected via cables suitable for each of the two gas springs, one or the other being controlled, depending on the direction of actuation of the pedal.

 This command can be done by various means within the reach of the skilled person and that is why they will not be described in detail here so as not to unnecessarily burden the description and the drawings.

 According to an important characteristic of the invention, the appuitête 9 can be retracted on the back of the backrest. As seen more particularly in Figure 2, the headrest 9 has the general shape of a "T" whose transverse branch is adapted to serve as support for the patient's head and whose vertical branch 91 is articulated in the file. The branch 91 has a section of approximately rectangular shape and is housed in a cavity 70 of complementary shape formed on the back of the backrest. The articulation axis 92 crosses the upper part of the cavity 70.

As can be easily understood from a simple observation of FIG. 3, this structure allows the headrest to tilt completely backwards and downwards, the headrest describing an angular stroke close to 1800. At the Figure 3 is symbolized by the arrow J the tilting movement, for its retraction, the headrest. The dashed outline 9 'represents the headrest in an intermediate tilting position; the outline in dashed lines 9 "represents the headrest in the low position, completely retracted. Means for locking the headrest in the raised position will be described below.

 According to another characteristic of the invention, the armchair is equipped with a pair of armrests 8. These are carried by tubular rods 80 preferably having an oblong section (the major axis of which corresponds to the longitudinal axis of the armchair). Each of the tubes 80 is guided in a plastic sleeve 81 which is fixed to the base and to the rear part of the seat 6 by means of a crosspiece 82. As will be seen below, with particular reference to the figure 7, the armrests 8 are movable in height by sliding the tubes 80 in the sleeves 81. It is thus possible to lower the armrests 8 at or slightly below the level of the patient's support surface on the seat. The armrests 8 can not only be lowered completely to the level of the seat, but they are also adjustable in height, as will be seen below with reference to FIG. 7.

 Preferably, and as is clearly visible in FIGS. 1 and 3, the tubes 80 are inclined relative to the vertical so as to have an orientation corresponding to an average inclination of the backrest 7. Thus, when adjusting the height of the armrests , their useful length serving as support for the patient's forearms, remains unchanged. It will also be noted that the rear part of the armrests 8 comes practically opposite the back of the backrest, so that there is no free space between the armrests and the backrest, in which the patient would risk to unexpectedly slide the armpits or part of the arms. This is therefore a factor of convenience and safety for the patient.

 As seen in Figure 5, there is provided at the upper part of the backrest, on the back thereof, recesses (cavities) 750, arranged symmetrically with respect to the plane of vertical and longitudinal symmetry of the chair on the edges of the backrest 7. A handle is mounted opposite each recess 750 which has the general shape of a "C". The handles preferably have an approximately circular section and have an ergonomic shape facilitating handling. The handles 75 are fixed to the backrest by any suitable means, for example using screws.

 The handles 75 delimit with the recesses 750 cavities 751 allowing the passage of the fingers during the grip of the handles by the caregiver, when he wishes to move the chair and his patient.

 Thanks to this arrangement, the handles fit perfectly on the back of the backrest, and do not, unlike known devices - whose handles have the shape of a handlebar - protruding parts capable of catching on obstacles and / or attack people who use the wheelchair.

 FIG. 7 shows an embodiment of the mounting means, with the possibility of height adjustment and retraction, of an armrest 8. The armrest 8 is formed from a plastic sheath surrounding a metal bar 88. This the latter is fixed, for example by welding, to the upper end of the tube 80 which has already been mentioned above. A nozzle 800 made of plastic, fixed (for example glued) to the lower end of the tube 80 serves as a stop preventing the escape to the top of the tube, out of its guide sleeve 81.

 In the inner wall of the sleeve 81 are formed several notches 810 located at different levels; their number is for example three.

 The blocking in the longitudinal direction, that is to say, in the height direction, of the tube 80 relative to the guide sleeve 81 is ensured by a latch 84. The latter consists of a small lever articulated around an axis 840 integral with the tube 80; it can protrude out of the tube, through an opening provided for this purpose, to come and enter one of the notches 810. A small spring 85 constantly tends to pivot the lever 84 in its locked position, projecting from the outside of the tube. The unlocking of the lock is ensured by a rod 83 which is actuated by a control lever 82 hingedly mounted in the upper part of the tube; of course, this lever also comes out of the tube so as to be easily accessible by the patient.

 By simply observing FIG. 7, it is understood that by pivoting the lever 82 upwards, as symbolized by the arrow I, one causes an upward pull on the rod 83 and the lock 84 is pivoted by such that it emerges from the notch 810 in which it was housed. If the control lever 82 is kept in the high position, the tube 80 is therefore free to slide axially in the sleeve 81. It therefore becomes possible either to completely lower the armrest into its retracted position, or to modify its position in height. If the lever 82 is released, the locking lever 84 again blocks the tube and the armrest 8 in the desired position. It is therefore very easy for the patient or his caregiver to adjust the armrests to adapt them to the size and morphology of the patient.

 The drawing of Figure 8 shows a possible locking mode of the headrest member 9. The metal frame of the headrest has been designated by the reference 93. As already said, the latter can pivot around a transverse axis 92 carried by the backrest.

 Above the axis 92 is fixed a stirrup 930 in which is mounted a locking rod 931. This can slide axially in the stirrup, in a substantially vertical direction. A helical compression spring 932 biases the rod 931 and constantly tends to move it upwards. An operating member 933 integral with the rod 931 makes it possible to move the latter downwards, against the force of the spring 932. The operating member 933 is easily accessible. I1 is for example housed inside a window 911 cut in the central part of the vertical branch 91 of the armrest (see FIG. 2).

 At the upper part of the backrest 7, of which only the metal frame has been shown in FIG. 8, is fixed a blocking piece 79. This carries on its underside a series of notches 790, for example the number of of them. These notches are adapted to serve as housing at the rounded end of the locking rod 931. The notches are offset from front to back, along the longitudinal axis of the chair. We therefore understand that by penetrating the locking rod 931 selectively into one or the other of the notches, it is possible to vary the inclination of the headrest relative to the backrest, and consequently to obtain good support. against the patient's head, whatever his morphology, whether he is more or less arched.

 To retract the headrest, it suffices to extract the rod 931 from the notch, by pressing down the control member 933; by pulling back on the headrest, it can be tilted down and back.

 In all of the above, we have not been interested in the structure of the three constituent elements of the seat -5, namely the seat 6, the backrest 7, and the headrest 9.

 In the embodiment of FIG. 9, these elements consist of a rigid shell, for example of thermoformed plastic material, carried by an appropriate metal frame, said shells removably receiving padding elements or cushions, against which the patient supports.

 In FIG. 9, the rigid shells of the seat 6, of the backrest 7, and of the headrest 9 have the general shape of a bowl, the opening of which is directed upwards and forwards. The bowls are respectively referenced 600, 700 and 900. Of course, these shells can advantageously be provided with reinforcing ribs, the design and location of which are within the reach of those skilled in the art. Each of the bowls is intended to receive a padding element 601, 701 and, respectively 901.

 Each of the cushions is of a similar design. Only one of them, namely the back cushion 701, has been shown in section in FIG. 6. The cushion 701 mainly comprises a filling element 78 constituted by a mass of flexible elastic deformable material, for example a synthetic foam. It has a curve adapted to the human anatomy, so that it can properly fit the patient's body. This element 78 is surrounded by a thin film 76 of plastic material, for example in skai. On the back of the cushion is fixed a plastic covering structure 77 intended to be applied against the shell 700.

 This type of cushion can be made simply by molding. For this, the film 76 is placed at the bottom of a mold of suitable shape in which the material which, after heating and expansion forms the filling 78, is placed. After extraction from the mold, the covering structure 77 is attached to the back of the cushion. .

 According to a very important characteristic of the invention, the cushions 601, 701, 901 are removably fixed by means of quick connection to their shell 600, 700 and 900 respectively.

In the example shown, the fixing means consist of gripping fabrics of the kind sold under the registered trademark
VELCRO. This type of connection is effected by means of two separable elements which are capable of gripping each other energetically.

One of the elements referenced 15 in Figure 9, consists of a thin plate provided on one of its faces with a plurality of hooks in semi-rigid synthetic material. The other element, referenced 16, has a face provided with a plurality of looped wires. When an element 16 is pressed against an element 15, the small hooks penetrate inside the loops, which causes entanglement ensuring relatively strong adhesion between the two elements.

 Each of the hulls 600, 700 and 900 is provided with several hooking elements 15 with hooks, glued and regularly distributed over the wall of the hull.

 On the back of the cushions 601, 701 and 901 are fixed, for example by gluing, elements 16 with loops, in corresponding locations.

 Thus, the attachment of a cushion against the associated shell is very simple. It suffices for this to correctly position the cushion relative to the shell and to apply it to the bottom of the latter.

Conversely, the operation of removing a cushion is also very simple, it suffices for that to carry out a frank traction of the cushion to move it away from the shell.

 We will now explain how the chair which has just been described is used to receive a person with reduced mobility.

 The caregiver first begins to operate the brake pads of the wheels, by operating one or the other of the pedals 31. The chair is thus immobilized on the floor S. Then, it deploys the market- feet 4 to bring it into a substantially horizontal position projecting from the base 1. By actuating the pedal 280, it then controls the pump / actuator device 28 to lower the seat.

This operation is illustrated in Figure 4. The lowering of the seat is done by causing the retraction of the jack 28. This has the effect of pulling back the control rod 26 and rotating the axis 25 in the direction arrow - The link 22, integral with this axis 25, is therefore lowered, which has the effect of causing the deformation of the articulated parallelogram 10, 20, 21, 22, bringing down the bent lever 20. The latter keeps a constant orientation, so that the seat 5 is content to descend, without varying its inclination. Thus, the height of the seat 6 changes from a value hl (Figure 3) to a much lower value h2 (Figure 4). Of course, this makes it easier for the patient to climb onto the chair.

 The nursing assistant then causes the armrests 8, or at least one of the armrests 8, to be retracted downwards, at the level of the seat 6; finally, it folds back the headrest 9.

 Conventionally, to help a person with reduced mobility to get into a chair, the caregiver takes it from behind, supporting him by the armpits.

 Assisted by his help, the patient begins by placing his foot or feet on the step platform 4. It should be noted that this is always at a very low level, completely accessible to the patient, since it is carried by a fixed-height element, namely the base 1.

 The presence of the support pad 41 under the step 4 prevents the chair from tipping unexpectedly forward when the patient's weight is carried on the step, as illustrated in FIG. 4A. Indeed, the fact that the protuberance 41 located under the platform 4 is very close to the ground S, this protuberance comes to rest on the ground from the start of the tilting, which is symbolized by the arrow K in FIG. 4A.

 Always assisted by his help, the patient then places himself in a seated position. It can do this by moving laterally and not necessarily back and forth on the seat, because at least one of the armrests 8 is retracted, at the level of the seat. Furthermore, the retraction of the headrest 9 behind the backrest facilitates the operation, this space being completely cleared for the caregiver, who, it should be remembered, supports the patient from behind by the armpits.

 When the patient is properly seated, the assistant or the patient raises the armrest (or armrests) to bring them to the optimal position, depending on the size and habits of the patient.

It also brings the headrest 9 back to the active position, against the neck and the back of the patient's head. I1 of course chooses the tilt position best suited to the more or less arched character of the patient. Finally, it lifts the seat, by actuation of the hydraulic device 28, causing the deformation of the mechanism 2 in the direction of lifting. Depending on the needs, it folds the step board or not in the retracted position.

 By actuating the gas springs 63 and / or 72, it can then improve comfort by playing on the inclination of the entire seat and / or the backrest only.

 With the patient seated in the chair, it is easy to move it.

 For this, the nursing assistant presses in the appropriate direction on one of the pedals 31 to release the brake. It can easily guide the chair during its movements by holding the handles 75. As already said, the orientation of one of the rear wheels can be blocked, always by operating one of the two pedals 31, in the event of circulation in a straight longitudinal direction.

 To make the patient leave the chair, it suffices to carry out the operations opposite to those which have just been described.

 Of course, the support pad 41 then also plays an interesting role, preventing the chair from tilting when the patient gets out of it.

 It frequently happens that the upholstery elements, that is to say the seat upholstery members are soiled, generally as a result of patient incontinence. As these elements, namely the cushions 601, 701 and 901 are removable, it is possible to change them easily.

 As a result of this removability, it is also possible to adapt cushions having different characteristics, in particular of material, color or hardness, to the same armchair structure. It is therefore easy for the manufacturer of this kind of armchair to offer customers products that are perfectly suited to their needs, without having to have large stocks of armchairs (only the cushions must be kept available in stock).

 Finally, it is important to note that the structure of the entire chair (with the exception of the removable cushions) is suitable for being able to be washed and disinfected under optimal conditions, for example with a jet of water and detergent and in washing and disinfection tunnels which already equip reception centers for people with reduced mobility. For this, all the constituent elements of the chair structure are made of materials such as plastic with high mechanical and thermal resistance and treated steel capable of withstanding the chemical and thermal conditions of this type of washing and disinfection treatment. . In addition, all of the control and actuation mechanisms of the movable parts of the chair are designed to be sheltered from treatment agents.

 The absence of stitching on the upholstery elements is an important factor of comfort for the patient, because the support on the chair is done regularly, which prevents the formation of bedsores even in case of prolonged use of the chair .

Claims (13)

 1. Armchair for person with reduced mobility, characterized in that it comprises  - a base (1) mounted on wheels (12)  - A seat (5) composed of a seat (6), a backrest (7) and a headrest (9), carried by said base (1)  - Adjustment means (2) which make it possible to adjust the height of the seat (5) relative to the base (1).  2. Chair according to claim 1, characterized in that said adjustment means comprise an articulated quadrilateral actuated by a hydraulic or pneumatic control member, for example a pump / jack device (28).  3. Chair according to one of claims 1 or 2, characterized in that it comprises a headrest (9) which is retractable by tilting (J) towards the rear of the backrest (7).  4. Chair according to claim 3, characterized in that the headrest (9) has the general shape of a "T" whose vertical branch (91) is housed and is articulated in a cavity (70) of complementary shape made on the back of the backrest (7), allowing the complete tilting of the headrest (9) backwards and downwards.  5. Chair according to one of claims 3 or 4, characterized in that the inclination of the headrest (9) relative to the backrest (7) is adjustable.  6. Chair according to one of claims 1 to 5, characterized in that the back of the backrest (7) has, at its upper part, two lateral recesses (750) and is provided with a pair of handles (75) arranged opposite these recesses, handle (75) and recess (750) delimiting a cavity with closed outline (751) for the passage of the fingers.  7. Chair according to one of claims 1 to 6, characterized in that the inclinations on the one hand of the entire seat (5) relative to the base (1) and on the other hand of the backrest (4) relative to the seat (6) are adjustable.  8. Chair according to one of the claims 1 to 7, characterized in that it is provided with a step (4) carried by the base (1) and retractable inside thereof.  9. Chair according to claim 8, characterized in that said step is provided with a protrusion (41) for support on the ground.  10. Armchair according to one of claims 1 to 9, characterized in that the seat (6), the backrest (7) and the headrest (9) include cushions (601, 701, 901) which are removable, quick fixing, for example by a fastening system (15-16) with gripping fabrics.  11. Chair according to claim 10, characterized in that said cushions (601, 701, 901) are formed of a plastic film (76) shaped on a flexible synthetic material (78), their face of support with the person without seam.  12. Chair according to one of claims 10 or 11, characterized in that, with the exception of the removable cushions (601, 701, 901), the entire chair is adapted to be washed and / or disinfected in a washing / disinfection tunnel.  13. Chair according to one of claims 1 to 12, characterized in that it comprises a pair of armrests (8) carried by the seat (6) and movable in height, these armrests (8) can be retracted by lowering at the seat.