Chair support assembly and procedure for operating said support assembly

ES3077350T3Undetermined Publication Date: 2026-08-31ARJO IP HOLDING AB (100 00)
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Patent Information

Application Number
ES2022843640T
Authority / Receiving Office
ES · ES
Patent Type
Patents
Current Assignee / Owner
Filing Date
2022-11-23
Publication Date
2026-08-31
Estimated Expiration
2042-11-23

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Abstract

A support assembly (1) for a chair (2) with a seat (3), the support assembly (1) comprising a base positioning unit (4) adapted to be installed on the chair (2), a seat (5), and a support element (6). The base positioning unit (4) comprises a top portion and two side walls arranged opposite each other, between which is a receiving compartment.
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Description

Chair support assembly and procedure for operating said support assembly Field of invention The present invention relates to a chair support assembly and a chair with a seat portion comprising a support assembly. The present invention further relates to a method for operating the support assembly. Background of the invention Chair support sets can be arranged to provide aid and support to individuals who require additional support, such as for their legs, head, or arms, while seated in a chair. For example, a patient may place their legs in a supportive position on a leg support while seated. Reasons for placing the legs in a supportive position on a leg support may include knee, joint, back, or other problems. A chair with a leg support set can be very helpful, as it can reduce potential pain, which may have arisen from, for example, back pain. A similar situation, related to support sets arranged for arms or heads, is when a patient, due to the support set, can obtain additional support and comfort while seated in a chair. Such a set is described in document US2012181838. Chair support assemblies can have various structures and mechanisms depending on how they are arranged and connected to the chair. Leg, head, or arm support assemblies are commonly attached to the chair with a multi-part mechanism. During patient care, it is common to assemble and disassemble a chair support assembly if, for example, it needs to be cleaned. It is also common for the support assembly to be pivotally adjustable to accommodate the patient's physical needs while seated in the chair. An example of a support assembly with assembly and release functionality, as well as the ability to pivot, is presented in US2013181498A1. A drawback of a support assembly as described in US2013181498A1 is that its pivoting mechanism comprises many different internal parts. All these parts together make operating, assembling, and disassembling the chair support assembly difficult and time-consuming. Compendium of the invention An object of the present invention is to provide a support assembly with a pivoting mechanism that is simple in its use and comprises few internal parts to facilitate operation compared to those of the prior art. In relation to the aforementioned object, a further object is to provide a method for operating a support assembly between an assembly and release position, an active position, and a passive position. These objects are achieved with a support assembly according to claim 1, a chair with a support assembly according to claim 17, and a method for operating the support assembly according to claim 18. The support assembly for a chair with a seat portion comprises a positioning base unit adapted to be disposed on the chair, a support portion, and a support element. The positioning base unit comprises a top portion and first and second side walls arranged opposite each other, such that a receiving compartment is disposed between the side walls.The support member comprises a first support arm with a first coupling portion where the first support arm is arranged with the support portion. The first coupling portion, when in an active position, is pivotally arranged with the receiving compartment in the positioning base unit and is engaged with the positioning base unit to alternate the position of the support portion between the active position and a mounting and release position. The support member comprises a second support arm, at least one of which is elastic relative to the other support arm to releasably engage with a coupling assembly arranged in the receiving compartment. An effect of the support arms being elastic relative to each other is that it allows the support arms to be pressed together.A person can, with their hand, grasp around the two support arms and firmly press the two support arms towards each other. According to one embodiment, the coupling assembly comprises first and second knob elements arranged on respective side walls, with the knob elements projecting from the respective side walls to each other. The knob element is attached to the inside of the side wall. One effect of the knob element is that it allows the knob elements to be releasably connected to the support arms when the support arm is arranged in the receiving compartment. An additional effect of the knob element is that when the support part is in the passive position, the knob element transfers part of the weight of the support part through the attached support arm. According to one embodiment, a first and a second shelf element are arranged on the respective side walls facing each other, on a lower portion of the positioning base unit. The shelf element is located in a peripheral region on the lower portion of the side wall, inside the shelf element. It extends away from the side wall surface, facing the center of the positioning base unit. The shelf element supports the support arm when the support assembly is in the active position. In the active position, the support arm pivots on the knob element and is simultaneously in contact with the shelf element. According to one embodiment, the receiving compartment comprises a central reinforcing element arranged with respective first and second reinforcing walls, which are oriented towards the respective side walls, thus providing a first space between the first side wall and the first reinforcing wall, and a second space between the second side wall and the second reinforcing wall. The central reinforcing element is arranged with the upper and lower portions of the positioning base unit. One effect of the central reinforcing element is that it creates stability and rigidity for the positioning base unit. According to one embodiment, the central reinforcing element comprises a recess extending between the first and second reinforcing walls. The recess extends between the first and second spaces. The recess is formed centrally within the receiving compartment, between the upper and lower portions, as well as between the first and second reinforcing walls. One effect of the recess is that it reduces stress concentrations in the material of the positioning base unit, which may arise during use. Reducing stress concentrations further reduces the risk of cracking in the material of the positioning base unit. According to one embodiment, in relation to the first and second spaces, the central reinforcement comprises respective first and second groove walls, which are arranged on the lower part of the support member. Compared to the respective reinforcement wall, each groove wall is positioned closer to its respective side wall. One effect of the respective groove walls is that they prevent the support arm from disengaging and falling out of the receiving compartment when the support assembly is in the active position. According to one embodiment, the first and second spaces comprise respective first and second grooves, where the first groove is defined between the first groove wall and the first side wall, and the second groove is defined between the second groove wall and the second side wall, with the respective first and second grooves extending from an entrance area of ​​the first and second spaces into an inner portion of the respective space, and with the respective groove arranged parallel to the respective side wall. The respective grooves are arranged in the respective first and second spaces on a lower portion and on each side of the central reinforcing element. The width of the respective groove is arranged to receive the coupling portion of the support arm.From the inner surface of the side wall toward the center of the positioning base unit, the combined width of a shelf element, in the indicated direction, along with the width of a slot, is shorter than the length of the knob element extending from the side wall. One effect of the slots is that they guide the support arms between the active and passive positions. An additional effect of the slots is that they prevent the support portion from moving laterally toward one side of the chair. According to one embodiment, the first and second support arms comprise respective first and second coupling parts adapted to engage with the coupling assembly in the first and second spaces, with elastic movement from at least one of the first and second support arms. The support arm comprises a metallic material. A second material having plastic characteristics encapsulates most of the length of the support arm. The first and second support arms are arranged parallel to each other and are connected to, and extend from, a frame arranged in the leg support assembly. The effect of the first and second coupling parts is that they engage and lock with the coupling assembly. According to one embodiment, each of the first and second coupling parts comprises a respective coupling surface, each of which includes a respective hole for coupling with the knob element in the respective first and second spaces. The hole has a diameter that is slightly larger than the diameter of the knob element. When the first and second support arms are pressed together and moved into the coupling position, the knob is adjusted and positioned in the hole of the coupling part as the respective support arm springs back to its original position upon release of the applied pressure. One effect of the hole is that it can receive the knob element and function as a connector between the positioning base unit and the support arm. According to one embodiment, the first and second coupling parts each comprise a respective sliding surface connected to the respective coupling surface and angled with respect to the respective coupling surface toward the other support arm. The effect of the angled sliding surface, when the support arm enters the coupling position, is that the support arm, with the angled sliding surface in sliding contact with the knob element, will move toward the other support arm. If the sliding surface were not angled, its edge would risk colliding with the knob element and thus preventing it from entering the coupling position.According to one embodiment, the respective sliding surfaces each comprise a rounded edge to fit an inner surface of the first and second respective spaces when the support arms apply pivoting movements with respect to the positioning base unit. One effect of the rounded edge is that the knob element can be positioned more centrally on the side wall compared to if the edges were not rounded, which would weaken the side wall structure since the knob would have to be positioned closer to the periphery of the side wall. According to one embodiment, the width of the respective mating surface, comprising the respective holes, is greater than the width of the respective support arm in the area where the plastic material terminates at the support arm. One effect of this increased width is that the mating portion, comprising the mating surface, is stronger and more rigid compared to if the area were not wider. According to one embodiment, in an assembly and release position, the first and second support arms, with their coupling parts, are arranged in the first and second respective spaces, such that the first coupling part is arranged to move elastically between the first side wall and the first reinforcing wall, passing through the first groove wall, and the second coupling part is arranged to move elastically between the second side wall and the second reinforcing wall, passing through the second groove wall. An effect of the assembly and release position is that in this position the support part can be mounted or released from its coupling with the positioning base unit.According to one embodiment, in an active position, the first and second support arms, with their coupling parts, are arranged in a lower region relative to the respective side wall. The first coupling part faces the first side wall, opposite the first slot wall, and is in support contact with the first shelf element. The second coupling part faces the second side wall, opposite the second slot wall, and is in support contact with the second shelf element (18b). In the active position, the support arms are not compressed; the knob elements are inserted into the holes in the support arms, and the support arms are in contact with the shelf elements. The shelf elements support and maintain the active position of the support part.In the active position, the respective walls of the slot, when accidentally released, lock the support arms. According to one embodiment, in a passive position, the first and second support arms, with their coupling parts, are arranged in their respective grooves. To enter the passive position, a compressive force is applied to the first and second support arms, pressing them toward each other and thus reducing the distance between the first and second coupling parts. In the positioning base unit, the grooves are parallel to each other. Furthermore, the distance between these parallel grooves is shorter than the distance between the opposite side walls. Additionally, the grooves are arranged to cooperate with the coupling assembly of the respective support arm. One effect of the respective groove is that it receives and guides the first and second support arms during their pivoting movement between the active and passive positions. According to one embodiment, the support assembly is a leg support assembly. One effect of the support assembly being a leg support assembly is that the leg support assembly will be able to provide support to a patient's legs while the patient is seated in the chair. According to one embodiment, the invention further relates to a chair with a seat portion comprising a support assembly. The support assembly comprises the features described above. According to one embodiment, the invention also relates to a method for operating the leg support assembly. More particularly, the method relates to coupling a support assembly between an assembly and release position, an active position, and a passive position, comprising the steps of: applying a compressive force against at least one of the first and second support arms, whereby the respective first and second coupling portions are arranged to move toward each other; - place the respective first and second coupling parts in the respective first and second spaces, in the receiving compartment; - release the compressive force against the first and second support arms, so that in the respective first and second spaces, the respective first and second coupling parts move away from the respective first and second reinforcing walls, towards the respective first and second side walls, the respective first and second sliding surfaces engage with the respective coupling assembly, arranged in the respective first and second spaces 20, 21 to the mounting and release position; - move the first and second support arms, with the respective coupling part, from the mounting and release position, with a pivoting motion, to be arranged opposite the respective slot walls and in support contact with the respective shelf elements to the active position; - apply a compressive force against at least one of the first and second support arms, so that their first and second coupling parts move towards the respective slot wall, towards each other and away from the respective shelf element, with the respective first and second coupling parts arranged in the first and second slot; - Apply a pivoting motion against the first and second support arms, whereby the first and second support arms, with their respective first and second coupling parts, move in their respective first and second slots from the active to the passive position. This procedure allows for the releasable coupling of the support part to the positioning base unit. One effect of this procedure is that the support part can be placed in the positioning base unit using a manual maneuver. During this manual maneuver, the hand grasps the first and second support arms and firmly squeezes them together, while simultaneously moving the support arms, with their respective coupling parts, into position in the receiving compartment of the positioning base unit. Upon releasing the support portion of the positioning base unit, the user grasps the support arms and lifts the support portion from the passive to the active position. In the active position, the user firmly squeezes the support arms, moving them toward each other and rotating them so that the coupling parts move away from the walls of the oppositely arranged slots and into the first and second spaces. In the respective first and second spaces, the coupling parts are pressed against the respective reinforcing walls, releasing the corresponding knob elements from their positions in the respective holes of the first and second coupling parts. Once the knobs are released from the holes, the support portion, along with the support arms, can be separated and moved away from the positioning base unit. Brief description of the drawings The invention is then described in more detail with reference to the accompanying drawings, where: Figure 1 is an overview of a chair with a support assembly in the assembly and release position. Figure 2 is an overview of the chair with the support assembly in the active position. Fig 3 is an overview of a chair with the support assembly in a passive position. Fig 4 is a view from below of a base positioning unit along with cross-section views AA, BB, CC and DD. Fig 5 is a view from below of the base positioning unit, separated from the support arms arranged with the support part. Fig 6 is a view from below of the support arms, entering into a docking position with the base positioning unit. Fig 7 is a view from below of the support arms, in an active position with the base positioning unit. Fig 8 is a view from below of the support assembly, in active position, together with a cross-sectional AA view. Detailed description of the preferred embodiment of the invention Figures 1, 2, and 3 illustrate a chair 2 with a seat portion 3. The chair 2, as illustrated in the figures, is equipped with a lifting mechanism and casters, preferably for seating a patient. The seat portion 3 is equipped with a support assembly 1. The seat portion 3 comprises a backrest and a front portion, the front portion of which, in this context, is the part that is visible when a person sits on the seat portion 3 and bends their lower legs downward. The support assembly 1 comprises a positioning base unit 4, a support portion 5, and a support member 6. The support member 6 is connected to the support portion 5. The positioning base unit 4 is located on the underside and front of the seat portion 3. The support member 6 is detachably connected to the positioning base unit 4.In the coupling position between the positioning base unit 4 and the support member 6, the support member 6 together with the connected support part 5 can be arranged in a mounting and release position 31, Fig 1, an active position 12, Fig 2, or in a passive position 13, Fig 3. Figure 4 illustrates the positioning base unit 4 with four cross-section lines AA, BB, CC, and DD to illustrate the design and construction of the positioning base unit 4 through the different sections AA, BB, CC, and DD. The positioning base unit 4 comprises an upper portion 7, which is arranged to join against the lower portion of the seat portion 3, as shown in Figures 1 and 2. The positioning base unit 4 further comprises an entrance area 24. The entrance area 24 is an opening, which is arranged between a first and a second side wall 8a, 8b, which are opposite and parallel to each other. The respective side walls 8a, 8b are further arranged between the peripheral regions of the upper portion 7 and a lower portion 17 of the positioning base unit 4.In a position where the base positioning unit 4 and seat part 3 are arranged relative to each other, Fig 1-3, the entry area 24 is arranged to face the front of seat part 3. Fig 4, section AA and BB, illustrates the entrance area 24, which is an opening, leading to a receiving compartment 9. With reference to Fig. 4, sections CC and DD, the receiving compartment 9 is defined by the opposing inner side walls 8a and 8b, the upper part 7, and the lower part 17 of the positioning base unit 4. The receiving compartment 9 comprises a first space 20, a second space 21, and a recess 22 between the first and second spaces 20 and 21. The recess 22 is located in a central reinforcing element 19, which connects the upper part 7 to the lower part 17. The recess 19 is attached to a first reinforcing wall 32a and a second reinforcing wall 32b. The first space 20 is defined between the first side wall 8a and the first reinforcing wall 32a. The second space 21 is defined between the second side wall 8b and the second reinforcing wall 32b. Inside the respective first and second side walls 8a, 8b, towards the lower portion 17, are arranged the respective first and second shelf elements 18a, 18b. The respective shelf elements 18a, 18b are arranged opposite each other. On the lower portion 17 of the reinforcing element 19, there are a first and a second slot wall 33a, 33b. Between the first shelf element 18a and the first slot wall 33a, there is a first slot 23a. Between the second shelf element 18b and the second slot wall 33b, there is a second slot 23b. The respective slots 23a, 23b extend parallel to the respective side walls 8a, 8b. The respective slots 23a, 23b further extend from the inlet area 24 into an inner wall of the respective first and second space 20, 21. The respective first and second space 20, 21 comprise a respective first and second coupling assembly 14a, 14b.The respective coupling assemblies 14a, 14b comprise respective first and second knob elements 15a, 15b. The respective knob elements 15a, 15b are arranged on the respective interiors of the opposite side walls 8a, 8b. The respective knob elements 15a, 15b are attached to the respective interior side walls 8a, 8b by, for example, glue, welding, brazing, screws, bolts, or other means. Furthermore, the knob elements 15a, 15b may be formed or manufactured together with the side walls 8a, 8b or the positioning base unit 4.The knob elements 15a, 15b, see Fig 4 DD, viewed from inside the side walls 8a, 8b, have a length that is longer than the combined length, in the same direction, of a shelf element 18a, 18b and a slot 23a, 23b arranged in space 20, 21. Figure 5 illustrates support assembly 1 in a detached position. In this position, support part 5 can be stored or, for example, taken to another facility for cleaning. Support part 5 comprises the first support arm 6a and the second support arm 6b. The first and second support arms 6a and 6b are parallel to each other and are connected to a frame 30, which is arranged with support part 5. The first and second support arms 6a and 6b form a unit together with support part 5. The support arms 6a and 6b extend outward from one side of support part 5. The first and second support arms 6a, 6b each comprise a respective first and second end portion 25a, 25b. These first and second end portions 25a, 25b are interconnected with the frame 30 of the support portion 5 via respective first and second connection areas 10a, 10b. Opposite the named end portions 25a, 25b of the respective first and second support arms 6a, 6b is a respective first and second coupling portion 11a, 11b. Each first and second coupling portion 11a, 11b comprises a coupling surface 26a, 26b and a sliding surface 28a, 28b. The respective coupling surfaces 26a, 26b comprise a respective hole 27a, 27b. The respective sliding surfaces 28a, 28b border the respective coupling surfaces 26a, 26b.The respective sliding surfaces 28a, 28b are inclined towards each other with respect to the parallel extension of the respective first and second support arms 6a, 6b. Each of the respective sliding surfaces 28a, 28b comprises a rounded edge 29a, 29b, as shown in Fig. 8, to fit an inner surface of the respective first and second space 20, 21 when the support arms 6a, 6b apply pivoting movements with respect to the positioning base unit 4. Fig 6 illustrates a force F applied against the first and second support arms 6a, 6b, so that the support arms 6a, 6b with the first and second coupling parts 11a, 11b are arranged to move towards each other. The support arms 6a, 6b are made of a material with elastic characteristics, so the support arms 6a, 6b can elastically return to their original shape or position when the force F ceases. In the movement when the support arms 6a, 6b are pressed together, the support arms 6a, 6b can move to the coupling position with the respective first and second coupling parts 11a, 11b, Fig. 6. When the coupling parts 11a, 11b enter the space 20, 21, the angled sliding surfaces 28a, 28b are arranged to slide into the knob element 15a, 15b in the respective spaces 20, 21.The angled sliding surfaces 28a, 28b contribute, as the coupling parts 11a, 11b move into the respective space 20, 21 and slide against the knob elements 15a, 15b, to the respective support arms 6a, 6b being pressed together. The angled sliding surfaces 28a, 28b border the coupling surfaces 26a, 26b, which comprise an opening 27a, 27b arranged to receive the respective knob elements 15a, 15b. Figure 7 illustrates the respective coupling parts 11a and 11b positioned in the coupling position in spaces 20 and 21. Holes 27a and 27b are arranged to receive knob elements 15a and 15b, so the support arms 6a and 6b have elastically returned to substantially their original position. In this position, the support arms 6a and 6b are connected to knob elements 15a and 15b and have entered the assembly and release position as shown in Figure 1. In a second stage, after the assembly and release position, the respective coupling parts 11a and 11b will pivot towards the respective shelf elements 18a and 18b and make contact with them, so the support assembly 1 will be in the active position as shown in Figure 2. In the situation where support assembly 1 is on chair 2 but in a passive position 13 (see Fig. 3), support assembly 1 can be tilted to facilitate the movement of a patient seated in chair 2. The passive position 13 is obtained by lightly pressing the support arms 6a, 6b, which are in the active position 12, since the knob elements 15a, 15 remain arranged in the holes 27a, 27b. From the active position 12, the support arms 6a, 6b are lightly pressed together, so that the respective coupling parts 11a, 11b are released from the shelf elements 18a, 18b and arranged towards the respective first and second slot walls 33a, 33b. In this position, the support arms are then slidably arranged in slots 23a, 23b, arranged to pivot away from the inlet area 24, towards respective end portions of slots 23a, 23b.The respective end portions in the respective slots 23a, 23b are arranged opposite each other with respect to the inlet area 24. To release the support arms 6a, 6b, they must pivot from their passive position 13 in their respective slots 23a, 23b to the active position 12, as shown in Fig. 2. In the active position 12, a force F is applied to the support arms 6a, 6b, allowing them to be pressed together until the respective coupling parts 11a, 11b stop moving further along the respective slot walls 33a, 33b. To release the support arms 6a, 6b, they must pivot away from the respective shelf element 18a, 18b and the respective slot walls 33a, 33b.In the first and second spaces 20, 21, the respective coupling parts 11a, 11b are allowed to be pressed further together and against the respective reinforcing walls 32a, 32b until the respective knob elements 15a, 15b are released and no longer engaged in the respective holes 27a, 27b of the respective coupling parts 11a, 11b. In this position, the support assembly is now in the release position 31, so the support arms 6a, 6b can be separated from the positioning base unit 4. Figure 8 illustrates the lower portion of support part 5 comprising a frame 30 extending around the periphery of the lower portion of support part 5. Support arms 6a, 6b are arranged with the frame 30 at connection areas 10a, 10b on the frame 30. Figure 8, section AA, illustrates a cross-sectional view of the support part 5 in an active position 12. In the active position 12, the support arms 6a and 6b are arranged substantially parallel to each other and not pressed together. Furthermore, in the active position 12, the coupling parts 11a and 11b are coupled through their provided holes 27a and 27b, with the knob elements 15a and 15b, and in contact with the shelf elements 18a and 18b. The lower edges of the respective coupling parts 11a and 11b are arranged to contact the respective shelf element 18a and 18b. In this position, the support arms 6a and 6b, with the support part 5, are arranged in a position between substantially horizontal and partially inclined downwards. Active position 12 is a position arranged between the assembly and release position 31 and the passive position 13 as shown in Fig 1-3. It has been previously described that the support system should be placed on a chair, preferably a patient chair. It will be appreciated that the principles described above can also be applied to other types of chairs and various types of support systems, such as leg, head, or arm supports. Reference signs: 1 set of support for, for example, the legs 2 chairs 3rd part of seat 4 base positioning unit 5. Support part for, for example, the legs 6 support member 6a first support arm 6b second support arm 7 top 8a first side wall 8b second side wall 9 reception compartment 10th first connection area 10b second connection area 11a first coupling part 11b second part of coupling 12 active position 13 passive position 14a, b coupling assembly 15a first knob element 15b second knob element 16a, b edge projection element 17 bottom 18a first shelf item 18b second shelf element 19 central reinforcement element 20 first space 21 second space 22 reduction 23rd first slot 23b second slot 24 entrance area 25a first part of the end 25b second part of end 26a, b coupling surface 27a, b hole 28a, b sliding surface 29a, b rounded edge 30th frame 31 mounting position and release 32a first reinforcement wall 32b second reinforcement wall 33a first slot wall 33b second slot wall F force

Claims

1. A support assembly (1) for a chair (2) with a seat portion (3), the support assembly (1) comprising: a positioning base unit (4) adapted to be disposed on the chair (2); a support portion (5); a support member (6); the positioning base unit (4) comprising an upper portion (7), and first and second side walls (8a, 8b) arranged opposite each other, whereby a receiving compartment (9) is disposed between the side walls (8a, 8b), the support member (6) comprising a first support arm (6a), with a first coupling portion (11a) wherein the first support arm (6a) is disposed with the support portion (5), the first coupling portion (11a), which is in an active position (12), pivotally disposed with the receiving compartment (9) in the positioning base unit (4),and adopted with respect to the base positioning unit (4) to alternate the position of the support part (5) between the active position (12) and a mounting and release position (31); characterized in that the support member (6) comprises a second support arm (6b) of which at least one of the support arms (6a, 6b) is elastic, with respect to the other support arm (6a, 6b), to releasably engage with a coupling assembly (14a, 14b) disposed in the receiving compartment (9).

2. A support assembly (1) according to claim 1, wherein the coupling assembly (14a, 14b) comprises a first and a second knob element (15a, 15b) disposed on the respective side walls (8a, 8b), and wherein the respective knob elements (15a, 15b) protrude from the respective side walls (8a, 8b) relative to each other.

3. A support assembly (1) according to any of claims 1 to 2, wherein on the wall (8a,8b) respective side walls oriented towards each other, in a lower part (17) of the positioning base unit (4), a first and second respective shelf elements (18a, 18b) are arranged projecting from the respective side wall (8a, 8b) and from each other.

4. A support assembly (1) according to claim 1, wherein the receiving compartment (9) comprises a central reinforcing element (19) arranged with a first and a second respective reinforcing wall (32a, 32b), which are oriented towards the respective side walls (8a, 8b), wherein a first space (20) is arranged between the first side wall (8a) and the first reinforcing wall (32a), and wherein a second space (21) is arranged between the second side wall (8b) and the second reinforcing wall (32b).

5. A support assembly (1) according to claim 4,wherein the central reinforcing element (19) comprises a recess (22) extending between the first and second reinforcing walls (32a, 32b).

6. A support assembly (1) according to claim 5, wherein, with respect to the first and second spaces (20, 21), the central reinforcing element (19) comprises respective first and second groove walls (33a, 33b) arranged in the lower portion (17) of the positioning base unit (4), which, compared to the respective reinforcing wall (32a, 32b), are arranged at a distance closer to the respective lateral wall (8a, 8b) than to the respective reinforcing wall (32a, 32b).

7. A support assembly (1) according to claim 4, wherein the first and second space (20, 21) comprise a respective first and second slot (23a, 23b), wherein the first slot (23a) is defined between the first slot wall (33a) and the first side wall (8a),and the second slot (23b) is defined between the second slot wall (33b) and the second side wall (8b), wherein the respective first and second slots (23a, 23b) extend from an entrance area (24) of the first and second spaces (20, 21) into an inner portion of the respective space (20, 21), and with the respective slot (23a, 23b) arranged parallel to the respective side wall (8a, 8b).

8. A support assembly (1) according to claim 1, wherein the first and second support arms (6a, 6b) comprise respective first and second coupling portions (11a, 11b) adapted to engage with the coupling assembly (14a, 14b) in the first and second spaces (20, 21), with elastic movement from at least one of the first and second support arms (6a, 6b).

9. A support assembly (1) according to claim 8, wherein the first and second coupling parts (11a, 11b) each comprise a surface (26a,26b) respective coupling, comprising a respective hole (27a, 27b) for coupling with the knob element (15a, 15b) in the respective first and second spaces (20, 21).

10. A support assembly (1) according to claim 9, wherein the first and second coupling parts (11a, 11b) each comprise a respective sliding surface (28a, 28b) that is connected to the respective coupling surface (26a, 26b) and is angled with respect to the respective coupling surface (26a, 26b) towards the other support arm (6a, 6b).

11. A support assembly (1) according to claim 10, wherein each of the respective sliding surfaces (28a, 28b) comprises a rounded edge (29a, 29b) to fit an inner surface of the respective first and second spaces (20, 21) when the arms (6a,6b) support apply pivoting movements with respect to the positioning base unit (4).

12. A support assembly (1) according to claim 9, wherein the width of the respective coupling surface (26a, 26b) over its area, comprising the respective holes (27a, 27b), is longer than the width of the respective support arm (6a, 6b), in the area where the plastic material terminates at the support arm (6a, 6b).

13. A support assembly (1) according to claim 6, in an assembly and release position (31), the first and second support arms (6a, 6b), with their coupling parts (11a, 11b), are arranged in the respective first and second spaces (20, 21), wherein the first coupling part (11a) is arranged to move elastically between the first side wall (8a) and the first reinforcing wall (32a), passing through the first groove wall (33a),and where the second coupling part (11b) is arranged to move elastically between the second side wall (8b) and the second reinforcing wall (32b), passing through the second slot wall (33b).

14. A support assembly (1) according to claim 6, in an active position (12), the first and second support arms (6a, 6b), with their coupling parts (11a, 11b), are arranged in a lower region with respect to the respective side wall (8a, 8b), where the first coupling part (11a) is arranged towards the first side wall (8a), opposite the first slot wall (33a) and in support contact with the first shelf element (18a), and where the second coupling part (11b) is arranged towards the second side wall (8b), opposite the second slot wall (33b) and in support contact with the second shelf element (18b).

15. A support assembly (1) according to claim 7, in a passive position (13),The first and second support arms (6a, 6b), with their coupling parts (11a, 11b), are arranged in the respective groove (23a, 23b).

16. A support assembly (1) according to any of claims 1 to 15, wherein the support assembly (1) is a leg support assembly.

17. A chair (2) with a seat portion (3) comprising a support assembly (1) according to any one of claims 1 to 16.

18. A method for coupling a support assembly (1) between an assembly and release position (31), an active position (12), and a passive position (13) according to any one of claims 1-17 comprising the steps of: - applying a compressive force F against at least one of the first and second support arms (6a, 6b), whereby the respective first and second coupling portions (11a, 11b) are arranged to move towards each other; - arranging the respective first and second portions (11a, 11b)11b) coupling in the respective first and second spaces (20, 21), in the receiving compartment (9); - releasing the compressive force F against the first and second support arms (6a, 6b), so that in the respective first and second spaces (20, 21), the respective first and second coupling parts (11a, 11b) move away from the respective first and second reinforcing walls (32a, 32b), towards the respective first and second side walls (8a, 8b), the respective first and second sliding surfaces (28a, 28b) engage with the respective coupling assembly (14a, 14b), arranged in the respective first and second spaces (20, 21) in the mounting and release position (31); - move the first and second support arms (6a, 6b), with their respective coupling parts (11a, 11b), from the assembly and release position (31) with a pivoting motion, towards their arrangement opposite the respective walls (33a,33b) of the slot and in support contact with the respective shelf elements (18a, 18b) to the active position (12); - apply a compressive force F against at least one of the first and second support arms (6a, 6b) so that their first and second coupling parts (11a, 11b) move towards the respective slot wall (33a, b), towards each other, and away from the respective shelf element (18a, 18b), with the respective first and second coupling parts (11a, 11b) arranged in the first and second slots (23a, 23b); - apply a pivoting motion against the first and second support arms (6a, 6b) whereby the first and second support arms (6a, 6b), with the respective first and second coupling parts (11a, 11b), move in the respective first and second slots (23a, 23b) from the active position (12) to the passive position (13).