FR3147094A1 - Armchair with removable back section - Google Patents

Abstract

Armchair with a removable back portion Armchair (10), for example a medical chair, comprising a base (20) intended to rest on a floor, a seat portion (50) configured to cooperate with said base so as to form a seat for the chair, and a back portion (60) configured to be mounted to said base in order to form a backrest for the chair, said back portion being configured to be mounted to said base in a removable manner. Abstract: Fig. 1.

Description

Armchair with removable back section

The present invention relates to the technical field of armchairs, and in particular medical armchairs generally used in hospitals. These medical armchairs are usually placed in patients' rooms and allow them to sit down and thus not remain lying in their bed throughout their hospitalization.

Traditional medical chairs comprise a base, a seat portion and a backrest fixed to the seat portion. A disadvantage of known chairs is that they do not meet hospital requirements in terms of hygiene. In particular, these chairs are generally made of materials likely to capture and store dust and pollutant particles. In addition, these chairs include many recesses and many hard-to-reach areas where dust can accumulate and which are difficult to clean. For example, it is particularly difficult to carry out satisfactory cleaning at the level of the gap formed between the seat portion and the backrest of the chair.

There is therefore a significant risk of contamination of known chairs and therefore of endangering the health of the patient. These chairs are therefore unhygienic and are therefore not suitable for use in hospitals or any other environment where hygiene standards are particularly strict.

An aim of the present invention is to propose an armchair which overcomes the aforementioned drawbacks.

To this end, the invention relates to an armchair, for example a medical armchair, comprising a base intended to rest on a floor, a seat portion configured to cooperate with said base so as to form a seat for the armchair, and a back portion configured to be mounted to said base in order to form a backrest for the armchair, characterized in that said back portion is configured to be mounted to said base in a removable manner.

The chair according to the invention is particularly suitable for use in a hospital environment. The chair according to the invention is preferably a medical chair.

Preferably, the base is formed essentially of metallic material.

The base preferably comprises at least two feet, preferably at least three feet, more preferably four feet.

Preferably, the base comprises a first leg, a second leg, a third leg and a fourth leg.

The base advantageously comprises a first base portion comprising the first and second legs, and a second base portion comprising the first and second legs. The first and second base portions preferably extend on either side of a vertical plane of symmetry of the chair passing through a longitudinal direction of the base. Preferably, the legs of the base each have the shape of an elongated plate. In other words, said legs have a thickness much less than their width, itself much less than their length. One advantage is to reduce the surface area of said legs on which dust can accumulate.

Preferably, the first leg portion has an angled portion formed between the first and second legs. Preferably, the second leg portion has an angled portion formed between the third and fourth legs.

Preferably, the second foot is inclined relative to the first foot at an angle of between 60° and 120°, preferably at an angle of between 80° and 100°, more preferably at an angle approximately equal to 90°.

The base advantageously comprises a crossbar extending between the first base portion and the second base portion. Preferably, said crossbar extends between the bent portion of the first base portion and the bent portion of the second base portion.

The first and second legs advantageously form a single-piece assembly. The third and fourth legs advantageously form a single-piece assembly.

Preferably, the base comprises a frame comprising said feet. The seat portion is advantageously mounted on said frame.

The back portion advantageously extends substantially vertically or slightly inclined relative to the vertical when it is mounted to the base. The seat portion extends transversely to the back portion. The seat portion extends substantially horizontally when it is mounted to the base.

When mounted on the base, the back portion forms a support on which the user can rest their back.

Preferably, but not limited to, the back portion is essentially made of a plastic material. In a non-limiting manner, said back portion may be made of any material suitable for medical use, preferably a material impermeable to dust or which does not tend to retain dust. The back portion advantageously comprises a stiffening frame embedded in a back body. Preferably, the back body is formed of a soft material, in order to improve the comfort of the user. Said stiffening frame advantageously has the shape of a “U”. The back portion has the general shape of a rectangular parallelepiped with a rectangular longitudinal section. In other words, said back portion has a length greater than its width, preferably greater than 1.5 times its width.

The dorsal portion advantageously comprises a front face, a rear face, a lower edge, an upper edge, a first lateral edge and a second lateral edge.

Preferably, the back portion is not connected to the seat portion.

Preferably, the seat portion is essentially made of a plastic material. The seat portion advantageously has the general shape of a rectangular parallelepiped with a square longitudinal section. In other words, said seat portion advantageously has a length substantially equal to its width, or slightly greater than its width.

According to the invention, the back portion is removably mounted to the base and can therefore be dismantled. By removable, it is meant that the back portion can be manually dismantled relative to the base by a user, without using a tool or exerting significant effort. The back portion can be dismantled without tools. The back portion is therefore not fixed to the base so that a user could not dismantle it without using a specific dismantling tool.

The back portion can then be easily disconnected from the base, which allows it to be cleaned completely without encountering any difficulty. The invention makes it possible to avoid the risk of dust accumulating in areas of the back portion that would be difficult to access, in particular at the level of the gap between the back portion and the seat portion. By dismantling the back portion, it is in particular easy to clean a lower part and a lower edge of the latter, which is inaccessible when the back portion is mounted on the base.

The chair according to the invention is therefore particularly hygienic and suitable for use in a hospital environment or any other environment where hygiene standards are strict.

Another advantage is that it allows the chair to be reduced in size, for example to be moved to another room or for storage.

In a non-limiting manner, said dorsal portion may be disassembled relative to the base only by pulling on said dorsal portion. Alternatively, said dorsal portion may be kept mounted to the base by means of a locking device, in which case the dorsal portion may be disassembled after having first acted on the locking device.

Advantageously, the chair further comprises a mounting device comprising at least one first mounting rod secured to the base or to said back portion, and at least one first mounting hole provided in the base when the first mounting rod is secured to the back portion or provided in the back portion when the first mounting rod is secured to the base, said first mounting rod being configured to engage removably in said first mounting hole for mounting the back portion to the base. The mounting device allows the back portion to be mounted to the base. The mounting device also allows the back portion to be held transversely to the seat portion. The first mounting rod prevents the back portion from moving in a direction transverse to said first mounting rod.

In addition, said first mounting rod makes it possible to guide the dorsal portion during its assembly to the base, as well as during its disassembly.

It is understood that when the first mounting rod is integral with the base, said first mounting hole is provided in the dorsal portion. Alternatively, it is understood that when the first mounting rod is integral with the dorsal portion, said first mounting hole is provided in the base, or in a portion of the base.

The engagement of the first mounting rod in the first mounting hole allows the mounting of the dorsal portion to the base.

Preferably, the first mounting rod is integral with the base, said first mounting hole being provided in the dorsal portion. In this non-limiting configuration, the first mounting rod extends inside the dorsal portion when the latter is mounted to the base. Said first mounting rod then also constitutes a stiffening element for the dorsal portion.

According to a particularly advantageous aspect, the base comprises said first mounting rod, the latter extending substantially vertically or slightly inclined relative to the vertical when the chair rests on said floor, and said first mounting hole is provided in a lower edge of said back portion. Said rod makes it possible to effectively maintain the back portion substantially vertically or slightly inclined relative to the vertical.

In this non-limiting configuration, the first mounting rod is secured to the base. It extends inside the dorsal portion when the latter is mounted to the base. The first mounting rod then extends into the thickness of the dorsal portion, between a front face and a rear face of the dorsal portion.

To disassemble the dorsal portion from the base, it is necessary to lift said dorsal portion in order to move it along said first mounting rod. An advantage is that said dorsal portion cannot be accidentally disconnected from the base.

Preferably, the mounting device further comprises a second mounting hole provided in said lower edge of the back portion, at a distance from the first mounting hole, and the base comprises a second mounting rod extending parallel to the first mounting rod, the second mounting rod being configured to removably engage in said second mounting hole for mounting the back portion to the base. The engagement of the first and second mounting rods respectively in the first and second mounting holes makes it possible to prevent the back portion from pivoting about the axis of the first mounting rod, about the axis of the second mounting rod, or about any other substantially vertical axis. The back portion is furthermore mounted all the more securely to the base of the chair.

It is understood that the distance between the first and second mounting holes is equal to the distance between the first and second mounting rods.

Preferably, the first mounting hole is provided in the lower edge of the dorsal portion proximate a first lateral edge of said dorsal portion. Preferably, the second mounting hole is provided in the lower edge of the dorsal portion proximate a second lateral edge of said dorsal portion, opposite the first lateral edge.

The distance between the first and second mounting holes is slightly less than the width of said dorsal portion.

Advantageously, the base comprises a frame and a mounting part pivotally mounted relative to the frame about a horizontal axis between at least a first position and a second position, said at least one first mounting rod being integral with said mounting part. One advantage is that it allows the inclination of the dorsal portion to be adjusted relative to the vertical. By pivoting the mounting part between the first position and the second position, about said horizontal axis, the inclination of the first mounting rod and therefore of the dorsal portion is modified relative to the vertical. This allows the user to adapt the inclination of the dorsal portion to their needs, which improves the ergonomics of the chair and the comfort of the user.

The first and second positions of the mounting piece correspond to two distinct inclinations of the dorsal portion.

Preferably, said mounting part is pivotable between at least three positions.

Preferably, said horizontal axis is transverse to a longitudinal direction of the base.

Advantageously, the first mounting rod and the mounting part form a single part. The first mounting rod advantageously extends transversely relative to the mounting part.

Preferably, the mounting part extends parallel to said horizontal axis. The mounting part advantageously comprises an elongate body, the first mounting rod extending transversely to said elongate body.

Preferably, the second mounting rod is also integral with the mounting part. Preferably, said second mounting rod and the mounting part form a single piece.

Preferably, the frame includes the legs of the chair.

Preferably, said chassis comprises a first lateral part and a second lateral part, said mounting part being pivotally mounted relative to said first and second lateral parts around said horizontal axis, so that it extends transversely between said first and second lateral parts.

Preferably, said first and second lateral parts each extend in a plane that is substantially vertical or slightly inclined relative to the vertical. Preferably, the first and second lateral parts have the shape of plates. The first and second lateral parts advantageously extend parallel to each other. The first and second lateral parts preferably extend on either side of the mounting part.

Preferably, the base extends in a longitudinal direction, said first and second lateral parts extending substantially parallel to said longitudinal direction of the base.

Preferably, the chair further comprises an actuating device arranged between the frame and said mounting part, the actuating device being configured to pivot the mounting part between the first position and the second position. The actuating device makes it possible to exert a force on said mounting part, causing it to pivot. One advantage is to facilitate the passage of the mounting part from the first to the second position and vice versa, and therefore to facilitate the adjustment of the inclination of the back portion.

The actuating device preferably comprises a cylinder disposed between the frame and the mounting part configured to pivot the mounting part between the first and second positions. The actuating device advantageously comprises a control member, for example a control lever, configured to actuate said cylinder.

Advantageously, the chair further comprises a locking device capable of taking a locking position in which it is configured to keep said back portion mounted on the base, as well as an unlocked position in which it allows the back portion to be dismantled. As long as it is not brought into the unlocked position, the locking device is configured to block the relative movement of the back portion relative to the base. The locking device makes it possible to block the mounting of the back portion on the base. It makes it possible to prevent the back portion from being accidentally dismantled from the base. The user's safety is therefore improved.

Preferably, the locking device comprises a tightening knob configured to cooperate with said back portion and the base so as to maintain said back portion mounted to the base when it is tightened. Preferably, the locking device is brought into the locking position when the tightening knob is brought into cooperation with the back portion as well as with the base, and is then tightened.

Preferably, the clamping knob cooperates with the mounting part of the base.

Preferably, a through locking hole is provided in the base, more preferably in the mounting part, the tightening knob comprising a threaded rod while a screw thread is provided in the dorsal portion, said threaded rod being configured to pass through said locking hole and to cooperate with the screw thread. Said screw thread is advantageously provided in the lower edge of the dorsal portion.

Alternatively and without departing from the scope of the invention, the dorsal portion may comprise a threaded rod configured to pass through said locking orifice, said tightening knob having a screw thread and being configured to be screwed onto said threaded rod to place the locking device in the locking position. Preferably, the threaded rod extends from the lower edge of the dorsal portion. Preferably, the threaded rod extends substantially parallel to the first mounting rod when the dorsal portion is mounted to the base.

Preferably, said through locking hole is provided in the mounting part of the base.

Advantageously, when said locking device is in the locked position, the tightening button and the dorsal portion extend on either side of the mounting part.

Advantageously, the locking device comprises at least a first magnetized portion secured to the base and at least a second magnetized portion secured to the back portion, the second magnetized portion being configured to cooperate with the first magnetized portion so as to keep said back portion mounted on the base. One advantage is to allow easy unlocking by exerting a force on said back portion. The magnetizing force of the two magnetized portions is advantageously sufficient to prevent accidental disassembly of the back portion relative to the base. In the locking position, the first magnetized portion cooperates with the second magnetized portion by magnetization. The locking device is brought into the unlocked position by separating the two magnetized portions and therefore by moving the back portion relative to the base in a disassembly direction.

Without limitation, the first magnetized portion may be a portion of the mounting part. Preferably, the mounting part is made of a metallic material.

Preferably, the locking device comprises a locking pin projecting from a lower edge of the dorsal portion and configured to engage with an opening provided in the base, said locking pin being provided with a friction element configured to keep said locking pin engaged in said opening. An advantage is to allow effective locking of the mounting of the dorsal portion to the base, while facilitating the placing in the unlocked position of the locking device.

The friction force exerted by the friction element between the locking pin and the dorsal portion opposes the disassembly of said dorsal portion relative to the base and thus ensures locking. The locking device is brought into the unlocked position by exerting a force on the dorsal portion aimed at moving said dorsal portion relative to the base in a disassembly direction. The force to be exerted on the dorsal portion must be greater than the friction force exerted by the friction element on said dorsal portion.

Preferably, said friction element comprises an O-ring mounted around said locking pin.

Without departing from the scope of the invention, the locking device may comprise one or more of the locking solutions described above. The locking device may for example jointly comprise a tightening button configured to cooperate with a screw thread formed in the back, as well as two magnetized portions. One advantage is to further improve the locking.

According to an advantageous aspect, said dorsal portion comprises a main part and a headrest configured to be mounted to the main part in a removable manner. An advantage of this headrest is to allow the user to rest his head in order to improve his comfort.

By removable, it is meant that the headrest can be manually disassembled from the main part of the back portion by a user, without using tools or exerting significant effort. This makes it easier and more efficient to clean said headrest.

Preferably, said headrest is configured to be connected to said main part by means of connection, for example connection rods.

Preferably, said headrest comprises a rear support portion on which the user can rest his head and at least one lateral support portion extending transversely to the rear support portion.

Advantageously, said seat portion is configured to be mounted to said base in a removable manner. By removable, it is meant that said seat portion can be manually disassembled from the base by a user, without using a tool or exerting significant effort. This makes it possible to clean said seat portion more easily and effectively.

It is therefore understood that, in this non-limiting variant, the back portion and the seat portion can be dismantled in relation to the base. Cleaning the base is therefore also made easier.

Advantageously, said base has a longitudinal direction, the base comprising at least a first transverse element and a second transverse element distant from the first transverse element, considered in said longitudinal direction, the first and second transverse elements extending transversely to said longitudinal direction, said seat portion being configured to cooperate with said first and second transverse elements for mounting the seat portion to the base.

The seat portion is configured to be removably mounted to said first and second cross members.

Preferably, said first and second transverse elements extend perpendicular to said longitudinal direction of the base. Said first and second transverse elements preferably extend parallel to each other.

Preferably, said first and second transverse elements extend between the first and second side portions of the chassis.

Preferably, at least one of said first and second transverse elements connects said first and second side portions of the chassis.

Preferably, the seat portion is provided with at least one connector configured to cooperate with said first transverse element and another connector configured to cooperate with said second transverse element.

Preferably, said connector has a housing configured to receive a transverse element.

Preferably, the seat portion comprises at least three connectors, more preferably four connectors.

The invention will be better understood on reading the following description of an embodiment of the invention given as a non-limiting example, with reference to the appended drawings, in which:

there is a perspective view of an embodiment of an armchair according to the invention;

there illustrates the base of the armchair of the ;

there shows the armchair of the , the dorsal portion having been dismantled;

there shows the armchair of the , the dorsal portion being shown transparent;

there illustrates the disassembly of the back portion of the chair from the ;

there shows a first variant of a locking device for the wheelchair of the ;

there shows a second variation of a wheelchair locking device from the ;

there shows a third variation of a wheelchair locking device ;

there is a front view of the chair of the , the seat portion and the back portion being shown transparent;

there illustrates the disassembly of the seat portion of the chair from the ; And

there illustrates a variation of the back portion of the chair of the .

The invention relates to an armchair, in particular a medical armchair, comprising a removable back portion.

There is a perspective view of an embodiment of an armchair according to the invention. The armchair 10 is here a medical armchair particularly suitable for use in a hospital environment.

According to the invention, the armchair comprises a base 20 , a seat portion 50 and a back portion 60 which will be described in more detail later. The back portion 60 is removably mounted to the base 20. In this non-limiting example, the seat portion 50 is also removably mounted to the base 20. The armchair 10 further comprises two armrests 12 fixed to the base.

There shows the base 20 of the armchair 10 , the back portion 60 and the seat portion 50 having been dismantled. For greater visibility, the seat portion 50 , the back portion 60 and the two armrests 12 are not shown in this figure. In this , it is noted that the base 20 extends in a longitudinal direction L. The base 20 comprises a frame 25 and a mounting part 40. The frame 25 comprises first 21 , second 22 , third 23 and fourth 24 feet configured to rest on the ground. The feet 21 , 22 , 23 , 24 each have the shape of an elongated plate.

The frame 25 comprises a first base portion 28 comprising the first and second legs 21 , 22. The first and second legs form a single piece. The first base portion 28 comprises a bent portion 29 connecting the first and second legs 21 , 22. Also, the second leg 22 is inclined relative to the first leg 21 , by an angle approximately equal to 90°. The frame 25 also comprises a second base portion 30 comprising the third and fourth legs 23 , 24. The third and fourth legs form a single piece. The second base portion 30 comprises a bent portion 31 connecting the third and fourth legs 23 , 24. Also, the fourth leg 24 is inclined relative to the third leg 23 , by an angle approximately equal to 90°. The first and second base portions 28 , 30 extend on either side of a vertical plane of longitudinal symmetry of the base 20 , passing through the longitudinal direction L.

The frame 25 further comprises a crossbar 32 extending transversely between the first base portion 28 and the second base portion 30. This crossbar 32 extends horizontally and substantially perpendicular to the longitudinal direction L of the base 20 .

The frame 25 further comprises a first lateral portion 33 and a second lateral portion 34. The first and second lateral portions 33 , 34 have substantially the shape of a plate and extend substantially parallel to each other, and parallel to the longitudinal direction L of the base 20. The first lateral portion 33 is arranged above the first base portion 28. The second lateral portion 34 is arranged above the second base portion 30 .

The first and second side parts33,34each have a front end33a,34a and a rear end33b ,34b. The front ends33a,34aof the first and second side parts33,34are connected to each other by a first transverse element3 5extending perpendicular to the longitudinal directionL. The first cross element35has the shape of a rod.

The frame further comprises a second transverse element 36 and a third transverse element 37 also having the shape of rods. The second transverse element 36 projects transversely from the first lateral part 33 , between the first and second lateral parts 33 , 34. The third transverse element 37 projects transversely from the second lateral part 34 , between the first and second lateral parts 33 , 34. The second and third transverse elements 36 , 37 extend horizontally and perpendicular to the longitudinal direction L of the base 20. The first and second transverse elements 36 , 37 extend in the extension of one another.

The second transverse element 36 has a length substantially equal to the length of the third transverse element 37. The second and third transverse elements 36 , 37 have a length less than the length of the first transverse element 35 , preferably less than one third of the length of the first transverse element. The first and second transverse elements 36 , 37 therefore each have a free distal end located between the first and second lateral parts 33 , 34 of the chassis 25 .

The mounting part 40 will now be described in more detail, with reference to the , on which the dorsal portion 60 and one of the armrests 12 are not shown, for greater readability.

On this , we note that the mounting part40is pivotally mounted relative to the chassis25 around an axisXhorizontal. The axisXextends perpendicular to the longitudinal directionLof the base20. More precisely, the mounting part40is pivotally mounted relative to the rear ends33b,34bof the first and second side parts33,34around said axisX. It therefore extends between the said rear ends.33b,34bof the first and second side parts33,34. The axisXcrosses said first and second lateral parts33,34

The mounting part comprises an elongated body 41 extending parallel to said axis X.

The chair 10 further comprises a first mounting rod 42 and a second mounting rod 44. In this non-limiting example, the first and second mounting rods 42 , 44 are integral with the mounting part 40. They are spaced apart from each other. The first and second mounting rods 42 , 44 and the mounting part 40 form a single part. The first and second mounting rods 42 , 44 project from the elongated body 41 of the mounting part, perpendicular to said elongated body 41. The first and second mounting rods extend substantially vertically, or slightly inclined relative to the vertical.

The mounting part 40 is configured to pivot relative to the chassis 25 , about the axis X , between at least a first position and a second position, each corresponding to an inclination of said first and second mounting rods 42 , 44 .

The mounting part 40 further comprises an actuating portion 46 projecting transversely to the elongated body 41. The chair 10 further comprises an actuating device 48 comprising in this non-limiting example a jack 49 arranged between the chassis 25 and said mounting part 40. More precisely, the jack 49 extends between the actuating portion 46 of the mounting part and the first transverse element 35 of the chassis 25. This jack 49 is configured to pivot the mounting part at least between the first position and the second position when it is actuated.

The actuating device 48 also comprises a control member 47 constituted here by a control lever 47 , configured to actuate said cylinder 49 and illustrated in . This control lever 47 advantageously extends partly under the seat portion and partly on the side of the seat portion. It is then easily accessible for the user seated on the seat portion 50 .

We will now describe the dorsal portion 60 with reference to FIGS. 4 and 5. On the , the dorsal portion 60 is shown transparent in order to illustrate its mounting on the base 20. The dorsal portion 60 has the general shape of a rectangular parallelepiped of rectangular longitudinal section. The dorsal portion 60 comprises a stiffening frame 62 embedded in a dorsal body 64 made of plastic material. Said stiffening frame 62 has the shape of an inverted “U”.

The dorsal portion 60 advantageously comprises a front face 65 , a rear face 66 , a lower edge 67 , an upper edge 68 , a first lateral edge 69 and a second lateral edge 70 .

In this non-limiting example, a first mounting hole 72 and a second mounting hole 74 , particularly visible in , are formed in the lower edge 67 of the dorsal portion 60 . These first and second mounting holes 72 , 74 are spaced apart by a distance substantially equal to the distance separating the first mounting rod 42 and the second mounting rod 44 . These first and second mounting holes 72 , 74 are formed between the front 65 and rear 66 faces of the dorsal portion 60 and extend parallel to these faces. In this non-limiting example, the stiffening frame 62 is hollow and extends from the lower edge 67 of the dorsal portion 60 . Said first and second mounting holes 7 2 , 7 4 extend inside said stiffening frame 62 .

As illustrated in , to removably mount the back portion 60 to the base 20 , the first and second mounting rods 42 , 44 are engaged respectively inside the first and second mounting holes 72 , 74 , so that they extend parallel to the front and rear faces 65 , 66 of the back portion. They also engage inside the stiffening frame 62. When said back portion 60 is mounted to the base 20, it forms a backrest for said chair 10 .

The first and second mounting rods 42 , 44 and the first and second mounting holes 72 , 74 form a mounting device 76 for the chair 10. This cooperation between the mounting rods 42 , 44 and the mounting holes 72 , 74 makes it possible to maintain the back portion 60 mounted on the base, transversely to the seat portion 50. The user can therefore rest his back on this back portion 60 without the latter tilting. When it is mounted on the base 20 , and as can be seen in , the dorsal portion 60 extends substantially vertically or slightly inclined relative to the vertical.

When mounted to the base, the dorsal portion 60 then cooperates with the mounting part 40 and is rotationally connected to said mounting part about the X axis. Also, by pivoting the mounting part 40 relative to the chassis 25 , about the X axis, by means of the actuating device 48 , it is possible to adjust the inclination of the dorsal portion 60 , thereby improving the comfort of the user.

The chair 10 further comprises a locking device 80 , 80' , 80'' capable of taking a locking position in which it is configured to hold the back portion 60 mounted on the base 20 , as well as an unlocked position in which it allows the back portion 60 to be dismantled.

Three variations of the locking device 80 , 80' , 80'' are illustrated in , 7 and 8 .

There shows a first variant of the locking device 80 of the chair 10. In this variant, the locking device 80 comprises a tightening knob 82 comprising a threaded rod 83. The locking device further comprises a screw thread 84 formed in the lower edge 67 of the back portion 60. In addition, the mounting part 40 of the base 20 has a through-hole locking orifice 43 formed in its elongated body 41. The threaded rod 83 of the tightening knob 82 is configured to extend through said locking orifice 43 and to engage with the screw thread 84 to place the locking device 80 in the locking position. The transition from the locking position to the unlocked position is achieved by tightening or loosening the tightening knob 82 .

There shows a second variation of the locking device80 'from the armchair10. In this variant, the mounting part40is made of metallic material and forms a first magnetized portion87. Furthermore, the locking device80'includes a first magnet86forming a second magnetic portion86and a second magnet88forming a third magnetic portion88. The two magnets86,88, and thus the second and third magnetized portions, are configured to cooperate by magnetization with the mounting part.40to place the locking device80'in the locking position. To place the locking device80'in the unlocked position, pull on the dorsal portion60in order to separate the two magnets86,88of the mounting part40.

There shows a third variant of the locking device 80 ' ' of the chair 10. In this variant, the locking device 80'' comprises a locking pin 90 projecting from the lower edge 67 of the back portion. The locking pin 90 comprises a friction element 92 , consisting in this non-limiting example of an O-ring arranged around the locking pin 90. In addition, an opening 45 is provided in the mounting part 40 of the base 20. To place the locking device 80'' in the locking position, the locking pin 90 is engaged in said opening 45. The friction element 92 then exerts a friction force on the mounting part 40 , thus keeping the locking pin 90 engaged in the opening 45 . To place the locking device 80 ' ' in the unlocked position, it is necessary to pull on the dorsal portion 60 in order to disengage the locking pin 90 from the opening 45 .

According to the invention, the dorsal portion 60 is removably mounted to the base. In other words, the user can manually dismantle the dorsal portion 60 relative to the base 20 without using a tool. One advantage is being able to easily clean the dorsal portion 60. To dismantle the dorsal portion, in a non-limiting manner, the user first brings the locking device 80 , 80' , 80'' into the unlocked position. He then moves the dorsal portion 60 so as to disengage the first and second mounting rods 42 , 44 relative to the first and second mounting holes 72 , 74 .

The assembly of the seat portion 50 to the base 20 will now be described with reference to FIGS. 5 , 9 and 10. As can be seen in , the seat portion 50 has the shape of a rectangular parallelepiped, with a substantially square longitudinal section. The seat portion 50 is, in a non-limiting manner, formed from a plastic material.

The seat portion 50 comprises an upper face 55 , on which the user can sit, and a lower face 56 arranged downward and facing the frame 25. The seat portion 50 is provided with first 51 , second 52 , third 53 and fourth 54 connectors projecting from the lower face 56. These connectors 51 , 52 , 53 , 54 each define an arc-shaped housing. The first and second connectors 51 , 52 are located near a front edge of the seat portion , while the third and fourth connectors 53 , 54 are located near a rear edge of the seat portion.

As illustrated in , to mount the seat portion 50 to the base 20 , and more precisely to the chassis 25 , in a removable manner, the first and second connectors 51 , 52 are configured to cooperate with the first transverse element 35. The third and fourth connectors 53 , 54 are configured to cooperate respectively with the second and third transverse elements 36 , 37. When the seat portion 50 is mounted to the base, the first transverse element 35 is engaged in the housings of the first and second connectors 51 , 52. Furthermore, the second transverse element 36 is engaged in the housing of the third connector 53 and the third transverse element 37 is engaged in the housing of the fourth connector 54 .

The seat portion is removably mounted to the base 20 and to the frame 25 . That is to say, it can be removed from the base 20 manually and without tools. To remove the seat portion 50 , it is necessary to pull on it, upwards, in order to disengage the first, second and third transverse elements 35 , 36 , 37 from the housings of the connectors 51 , 52 , 53 , 54 , as illustrated in The seat portion can then be cleaned easily and effectively.

There illustrates a variant of the back portion 60 of the chair 10 in which the latter comprises a main portion 61 and a headrest 63 configured to be removably mounted to the main portion. To this end, connection holes 65 are formed in the headrest 63 , while connection rods 71 project from the main portion 61 of the back portion. The connection rods 71 are configured to engage the connection holes 65 for removably mounting the headrest 63 to the main portion 61 .

Claims (13)

Armchair (10), for example a medical armchair, comprising a base (20) intended to rest on a floor, a seat portion (50) configured to cooperate with said base so as to form a seat for the armchair, and a back portion (60) configured to be mounted to said base in order to form a backrest for the armchair, characterized in that said back portion is configured to be mounted to said base in a removable manner. The chair of claim 1 , further comprising a mounting device (76) comprising at least one first mounting rod (42) secured to the base (20) or to said back portion (60), and at least one first mounting hole (72) provided in the base when the first mounting rod is secured to the back portion or provided in the back portion when the first mounting rod is secured to the base, said first mounting rod being configured to removably engage in said first mounting hole for mounting the back portion to the base. An armchair according to claim 2 , wherein the base (20) comprises said first mounting rod (42), the latter extending substantially vertically or slightly inclined relative to the vertical when the armchair (10) rests on said floor, and wherein said first mounting hole (72) is provided in a lower edge (67) of said back portion (60). The chair of claim 3 , wherein the mounting device (76) further comprises a second mounting hole (74) formed in said lower edge (67) of the back portion (60), spaced from the first mounting hole (72), and wherein the base (20) comprises a second mounting rod (44) extending parallel to the first mounting rod (42), the second mounting rod being configured to removably engage in said second mounting hole for mounting the back portion to the base. Armchair according to claim 3 or 4 , in which the base comprises a frame (25) and a mounting part (40) pivotally mounted relative to the frame about a horizontal axis (X) between at least a first position and a second position, said at least one first mounting rod (42) being integral with said mounting part. An armchair according to claim 5 , wherein said frame (25) comprises a first lateral part (33) and a second lateral part (34), said mounting part (40) being pivotally mounted relative to said first and second lateral parts about said horizontal axis (X), so that it extends transversely between said first and second lateral parts. An armchair according to claim 5 or 6 , further comprising an actuating device (48) disposed between the frame (25) and said mounting part (40), the actuating device being configured to pivot the mounting part between the first position and the second position. Armchair according to any one of claims 1 to 7 , further comprising a locking device (80) capable of taking a locking position in which it is configured to hold said dorsal portion (60) mounted on the base (20), as well as an unlocked position in which it allows the dorsal portion to be dismantled. An armchair according to claim 8 , wherein the locking device (80) comprises a tightening knob (82) configured to cooperate with said back portion (60) and the base (20) so as to maintain said back portion mounted to the base when tightened. Armchair according to claim 8 or 9 , in which the locking device (80) comprises at least a first magnetic portion (87) secured to the base (20) and at least a second magnetic portion (86, 88) secured to the back portion (60), the second magnetic portion being configured to cooperate with the first magnetic portion so as to keep said back portion mounted on the base. An armchair according to any one of claims 8 to 10 , wherein the locking device (80) comprises a locking pin (90) projecting from a lower edge (67) of the back portion (60) and configured to engage with an opening (45) provided in the base (20), said locking pin being provided with a friction element (92) configured to keep said locking pin engaged in said opening. An armchair according to any one of claims 1 to 11 , wherein said seat portion (50) is configured to be removably mounted to said base (20). Armchair according to claim 12 , wherein said base (20) has a longitudinal direction (L), the base comprising at least a first transverse element (35) and a second transverse element (36) distant from the first transverse element, considered in said longitudinal direction, the first and second transverse elements extending transversely to said longitudinal direction, said seat portion (50) being configured to cooperate with said first and second transverse elements for mounting the seat portion to the base.