Patent ID: 12251020

DETAILED DESCRIPTION OF THE INVENTION

The origin of the invention is related to transforming hinges and rotations of the human body into pivoting movements within a seating system, eventually creating a dynamic and innovative chair or seating assembly in general with ergonomic purposes in particular. Pressure points, skin integrity issues, blocked muscles, a sliding body, shear forces and tense and non-functional posture are reduced or even eliminated with the improved seating assembly in accordance with the invention. Further, the invention is challenged while translating such ergonomic and physiognomic system in a well-designed (wheel) chair, wherein all functions are integrated in an esthetically nice looking and apparently simple though rather subtle and very practical model. A solution is provided for both satisfying user and environment.

WithFIG.1Aan embodiment of the functional principle of a seating assembly100in accordance with the invention is presented schematically. The seating assembly100as depicted here comprises a basic frame or seat base unit101onto which a seat unit102and a back-support unit103are mounted. The basic frame101inFIG.1Ais positioned with its length L parallel to the floor115, or so-called set up horizontally. The seat unit102itself comprises of a seat or sitting122and a seat frame120, whereas the back-support unit103has a backrest108mounted onto a back-support frame110. Both seat frame120and back-support frame110are connected with the hip joint or trochanter point lying on the axis P perpendicular to the drawing surface, i.e. the surface ofFIG.1A. The hip joint or trochanter point is a pivot point at the level of the hip joint, also referred to as height h. This height h can vary and is for instance in the range of 50-60 cm or about 55 cm.

Further, both seat unit102and back-support unit103are connected with motion control means111,112,113,114such as for example gas springs or dampers, or actuators. As the word suggests these motion control means111,112,113,114are provided to control movement between the main parts of the seating assembly100. More in particular, a first type of motion control means111,112is shown connecting the sitting122with the basic frame101, and enabling a pivoting movement from front to back via means111, and a pivoting movement from back to front via means112. The motion control means111,112hence control the seat unit102to tilt forward and backward. The first type motion control means111,112can be locked or open. When locked, the seat base position or position of the sitting122remains fixed. When open, the seat base position or position of the sitting122can be changed or can adapt to the movement and/or muscle tone and/or position of the user. i.e. a person sitting on the seating assembly100. The motion control means111,112may come in pairs i.e. having one piece at one or each side of the seating assembly100, as better illustrated while referring to gas springs105,105′,106,106′, or first pair105,105′ and second pair106,106′ inFIG.1C.

A second type means113between seat unit102and back-support unit103will control movement of the back-support unit103, more in particular controlling the backrest108for reclining backward and pivoting back forward. The second type motion control means113can also be locked or open. When locked, the backrest108position will remain fixed. When open, the backrest108position can be changed or can adapt to the movement and/or muscle tone and/or position of the user or person sitting on the seat.

A third type means114between back-support unit103and basic frame101is provided for controlling fixation of the back-support unit103while maintaining a variable seat tilt, meaning controlling pivoting movement of the seat unit102while being fixed to the back-support unit103. Again, the third type motion control means114can be locked or open. When locked, the backrest108position remains fixed while the seat unit102can vary positions independently by means of second type motion control means113open, and variation of first type motion control means112,111(open or locked) for variations in seat unit102position. When open, back-support unit103and seat unit102movement can occur in conjunction providing seat and back-support tilt in space, with second type motion control means113locked and first type motion control means112,111open or locked for variations in seat unit102and back-support unit103together (tilt in space).

As shown inFIG.1A, the seat unit102or sitting122in particular comprises of a horizontal or sitting section122A and a vertical or back section122B. In other words, the seat unit102covers sitting including pelvis area. Referring in particular to the seat unit102comprising seat and pelvic support, according to an embodiment of the invention, it is possible to adjust the seat-to-pelvic angle defined as being the angle between the seat and the direction of pelvis as illustrated inFIG.8, for example by means of Velcro® Brand tape (a hook and loop fastener tape by Velcro Companies) for example in a wheelchair or another mechanism all or not controlled by means of an actuator.

InFIGS.8A and8Bthe seat-to-pelvic angle is indicated with2straight lines and a connecting elliptical hinge therebetween. InFIG.8Aa person is leaning backward and hence the seat-to-pelvic angle is more than 90°, whereas inFIG.8Bthe person is sitting straight up, and therefore the seat-to-pelvic angle is about 90°. In some occasions the seat-to-pelvic angle for (wheelchair) seat users may be fixed of limited in adjustment and therefore it may be necessary to be able to adjust it. For example, this is possible by sliding a bracket on the seat assembly frame and adjusting the tension of Velcro® Brand tape (a hook and loop fastener tape by Velcro Companies) provided onto the (wheelchair) seat such that movement of the pelvis can be followed. Moreover, this can be done by means of another mechanism to adjust the angle (at the height of the elliptical hinge inFIGS.8A and8B) and can also be performed by means of an actuator.

The back-support unit103covers lumbar and dorsal area. Hence, segmentation around anatomical movement axes is generated, which is further clarified as follows. With the present invention a seating assembly can be divided into specific parts or segments, wherein the well-chosen segments are for the correct and particular functioning of the seating assembly. According to an embodiment, following parts or segments, some elements thereof, or a combination of such elements, are particularly chosen for the seating assembly in accordance with the invention:Sitting122A and pelvis part122B of the seat unit102, which can be defined as the horizontal seat and the back section only at the height of the back of the pelvis;The back-support unit103, defined as the back section above the back of the pelvis.

Moreover, the seat unit102with sitting122A and pelvis part122B can be further segmented as:Partial sitting122A1, defined as the horizontal seat, taken from the back section though only up to the sitting knob160or ischial tuberosity, located at about ⅓ seat distance from the back section, including the back section or pelvis part122B;Partial sitting122A2, defined as the remaining ⅔ seat distance of the horizontal seat;Left and right split-up parts of all of the above seat unit segmentations, being individually operable.

In addition, the back-support unit103can also be further segmented as:Left and right split-up parts of all of the above back-support unit segmentations, being individually operable.

With the left and right split-up parts, asymmetric operation or movement of the seating assembly is feasible, such that people suffering for instance from hemiplegia or scoliosis can be particularly supported or accommodated in improved sitting comfort and alignment.

All of mentioned above parts or segments can either all move together, either independently or in sequence of each other around the hip joint (virtual or real) for an anatomical movement, and can independently from each other or together or in sequence, move dynamically (automatically) or statically (adjustable in a fixed manner). Such movement can be effected by different types of actuators (e.g. gas springs, polymers, motors), control systems (e.g. sensors, user pressure on segments, user movements) and operating systems (e.g. buttons, levers, electrical control). Depending on whether these parts or segments can either all move together, separately or in sequence, different sitting functions will be applicable.

Whereas inFIG.1Athe basic frame of seat base unit101is set up horizontally within the drawing.FIG.1Billustrates schematically another embodiment of the functional principle of a seating assembly in accordance with the invention, wherein the seat base unit101appears to be set up rather vertically with respect to the floor or ground115. In fact, the double-lined seat base unit101ofFIG.1Bis determined as having a first vertical part116perpendicular to a second horizontal part117, with the first vertical part116also being perpendicular to the ground115. The second horizontal part117of the T-structured seat base unit101is placed parallel with the floor115.

Further, inFIG.1Bonly one first type motion control means111is given for illustrating pivoting movement from front to back, while connecting the seat unit102in bold grey with the seat base unit101. The seat unit102is again also connected with the back-support unit103in bold black via second type motion control means113for controlling backrest108movement, as well as is provided a third type motion control means114between the back-support unit103and the seat base unit101for controlling sitting122movement while being fixed to the back-support. All motion control means111,113,114are represented in dashed line.

The backrest108represents an angle α with the normal N being perpendicular to the ground115. Moving the backrest108via motion control means113will change the angle α with the normal N. The position of the backrest108can hence be adapted with a person reclining in the seating assembly. While reclining, the angle α will increase, and decrease again when the person is leaning back forward. The arrows m1and m2indicate possible pivoting movements. As an example, measures of the seating assembly are for instance, for a height h of approximately 55 cm, having a horizontal part117of about 60 cm in length D, a seat depth d of ca. 45 cm, of which the distance to pivot point dP is ca. 20 cm, while seat height s is about 25 cm, of which the height to pivot point sP is about 10 cm. Height h can vary for instance in office chair applications. Further, all measures mentioned may vary depending on biometrical variations within user populations. With dP as defined here it becomes clear that the pivot point doesn't need to be centred with respect to the seat unit102, but moreover is lying closer towards the backrest108than to the front of the sitting122. In addition, for this particular example, the length b of the backrest108is e.g. 20 cm positioned at an angle α of e.g. 10° with the normal N.

FIG.1Cshows an embodiment of part of an ergonomic chair design as seating assembly100in accordance with the invention. Part of the seat base unit101is shown, onto which the seat unit102and the back-support unit103are mounted via the same pair of pivot points104lying on the common pivoting axis P. The first type motion control means for pivoting the seat unit102forward and backward are represented here by gas springs105,105′,106,106′, or first pair of gas springs105,105′ and second pair of gas springs106,106′, while connecting seat unit102with seat base unit101. Using other (type of) actuators instead of gas springs is also possible here. The second type of motion control means, for controlling pivoting movement of the back-support unit103, is now illustrated by gas spring107, while connecting seat unit102with back-support unit103. As an alternative to gas spring107, the connection and pivoting movement between seat unit102and back-support unit103may also be introduced via a pair of motion control means, and therefore gas springs117,117′ are displayed as another possible solution.

InFIG.1Da picture embodiment is given of an ergonomic chair prototype as seating assembly100in accordance with the invention. The first type of motion control means111,112are clearly illustrated on each side of the chair. The second type of motion control means113is here an actuator connecting seat unit102with back-support unit103. With this embodiment ofFIG.1D, as with the embodiment ofFIG.1C, the option of fixing the back-support unit103is no longer provided. In other words, the third type of motion control means114is not presented in these ergonomic chair examples. For non-medical applications this might be acceptable, whereas in wheelchairs or complex seating configurations for instance—having a medical purpose—the third type of motion control means114would be rather preferred.

InFIG.1Ean embodiment is illustrated of an ergonomic design chair comprising a seating assembly100in accordance with the invention. The seat base unit101is shown, onto which the seat unit102and the back-support unit103are mounted via the same pair of pivot points104lying on the common pivoting axis P. As inFIG.1C, gas springs106′,107(including gas spring106not visible) are also present here for motion control of seat unit102and back-support unit103. In this embodiment the gas spring105′ at the right inner chair side (including gas spring105at the left inner chair side) fromFIG.1Cis replaced by another type of actuator150′ (and a corresponding actuator paired with gas spring107and not visible) inFIG.1E, being for example a deformable polymer. In particular, this type of actuator is used instead of a gas spring because the little amount of change or scale in movement needed or required here for this kind of chair design. As said, although not visible inFIG.1E, the corresponding actuator that replaces the gas spring105, is also for example a deformable polymer. The deformable polymer is e.g. smaller in size or volume than the gas spring105,105′ miniaturizing and simplifying the motion control system provided within the chair design.

FIGS.2A,2B, and2Cillustrate alternative embodiments of the functional principle of the seating assembly100ofFIG.1A, representing other back-support frame architectures. As depicted inFIGS.2A and2C, the back-support frame210,210″ of the seating assembly200is not necessarily directly connecting the backrest208with the hip joint or trochanter point204. Indirect connection with the trochanter point204for different seating applications is herewith illustrated. Further, the back-support frame210′ can be partially curved as illustrated inFIG.2B.

While referring toFIGS.3A and3B, according to the invention, it is also possible to connect the seat unit302and the back-support unit303with the hip joint or trochanter point304in a virtual manner, i.e. connecting the units302,303respectively with a circular guiding rail309,319of which the centre is the hip joint or trochanter point304.FIG.3Aillustrates an embodiment for connecting the seating assembly's back-support unit303, more in particular its back-support frame310with the hip joint304in a virtual way via the guiding rail309, whileFIG.3Bshows an embodiment for connecting the seating assembly's seat unit302, more in particular its seat frame320with the hip joint304in a virtual way via the guiding rail319.

FIG.4illustrates an embodiment of a seating assembly400with guiding rails409,419in accordance with the invention. The back-support unit403is directly connected with the trochanter point404, while the back-support frame410is connected with a circular guiding rail409embedded in the seat base unit401and having its circle centre in the trochanter point404. The seat unit402is connected with another circular guiding rail419, also having its circle centre in the trochanter point404, and being embedded in the seat base unit401. The guiding rails409,419are provided with dampers or actuators411,412,414—or another type of motion control means—at the front and at the back. Between the two guiding rails409,419a further damper or actuator413is provided for controlling movement amongst each other, or fixing them together in a locked position such that seat unit402and back-support unit403are moving together as one entity. All other dampers or actuators411,412,414can also be open or locked in different sequences. For a particular embodiment based on the concept of the seating assembly400ofFIG.4, a chair with swing function could be presented. Especially in medical or healthcare applications, multiple variations of such swing chair could be very useful, such as e.g. provided with variable damping, all or not using electrical actuators, for patients with spasticity, or for anxious or agitated people.

Referring back to the use of gas springs as possible motion control means,FIGS.5A and5Bshow a specific embodiment of a seating assembly's gas springs set-up in accordance with the invention. Gas springs511,512are mounted onto the sitting522of a seat unit502for control pivoting movement of the seat unit502, or its sitting522in particular. InFIG.5A, the set-up is illustrated without motion, whereas inFIG.5B, motion simulation is outlined and indicated with the arrows. Virtual pivot point around the trochanter is generated by means of locking gas spring511and opening gas spring512, locking gas spring512and opening gas spring511, herewith controlling seat unit502tilt. A seat unit502tilt can be fixed in a particular position by locking both gas springs511,512.

In comparison,FIGS.5C and5Dillustrate an embodiment of a seating assembly's gas spring521in combination with rotating rod524following the circular shape523with one of its ends, whereas the other end is attached to the sitting522of the seat unit502. A seating assembly's seat unit502is here connected with hip joint in a virtual way in accordance with the invention, meaning that a virtual pivot point around the trochanter is generated. While controlling seat base tilt positions, inFIG.5C, the set-up is illustrated without motion, whereas inFIG.5Dmotion simulation is outlined and indicated by the fuzzy and overlapping images. The motions of gas spring set-up on one hand and of the hybrid set-up on the other hand are comparable, i.e. similar motion curves are generated for the two examples given. Similar mechanisms as described inFIGS.5A-5Dcan apply to the back-support unit (together with seat unit502or separated).

According to an embodiment of the invention, a wheelchair as a seating assembly600is considered inFIGS.6A-6Dillustrating schematically possible movements of such (wheel) chair. First, as depicted inFIG.6Athe inclination angle of the back-support unit603can be adapted when a person sitting in the wheelchair is reclining. The seat unit602can be tilted up or down separately or independently from the back-support unit603, being displayed inFIG.6B. Having the back-support unit603e.g. fixed to the seat unit602by means of third motion control means113as mentioned inFIG.1A, both can be pivoted together as one single unit, which is shown inFIG.6C. InFIG.6Dall possible pivoting movements fromFIGS.6A,6B, and6Care illustrated together.

According to an embodiment of the invention, existing chairs, or wheelchairs in particular, can be adjusted with a seating assembly in accordance with the invention, by means of a retrofit kit. Amongst the existing chairs in general, no limitations are considered, nor are particular types excluded. The method for installing such a retrofit kit for a seating assembly in accordance with the invention can be as follows:Removing the back and sitting part out of the existing wheelchair;Mounting a bracket on the existing frame to create a rotation point at the level of the hip joint;Adding a seat unit (horizontal seat+the pelvis part) and allowing it to move directly or indirectly around the rotation point. Optionally, the existing sitting part can be converted by adding a pelvis part (by means of a bracket);Placing an actuator that controls the movements of the seat unit (see different types and movement options as elsewhere mentioned with the invention, e.g. with the description ofFIGS.1A-1E);Placing a lumbar and dorsal back section that can also move directly or indirectly around the rotation point. Optionally, the existing back can be converted by removing a part of the back such that only lumbar and dorsal back part remains, while creating a connection by means of a bracket that connects the back part to the pivot point;Placing an actuator that controls the movements of the back unit (see different types and movement possibilities as elsewhere mentioned with the invention, e.g. with the description ofFIGS.1A-1E).

The retrofit kit can include a conversion of the seat unit and/or the back-support unit (for different heights) and/or a may provide in a partial segmentation of the seat unit, such as for instance ⅓ back seat and pelvic area, and ⅔ front seat. Moreover, the kit can be extended to an asymmetrical setting of the seat and/or back-support unit by means of actuators that are individually adjustable on the left and right. Asymmetrical setting for seat and/or back-support unit may enable for correction or adjustment in seating comfort of either left or right body parts in answer for instance to people suffering from scoliosis. Moreover, the kit can also comprise of a further segmentation of the front part (half to ⅔ of the front seat) of the seat unit movable around the same hip joint pivoting axis as used generally for seat unit and back-support unit in accordance with the invention, and hence offering more hip bending and stretching to be steered and controlled with actuators.

Different types of actuators could be applicable, while referring e.g. to those gas springs or electrically driven actuators as yet mentioned above. This should also be possible separately and independently of one another on the left and right to offer solutions for people with a hip disability or for enabling standing function. It is noted that the segmentation as described here for the particular application or embodiment of a retrofit kit is in fact to be also interpreted for a seating assembly in general in accordance with the invention, and thus no limitation in type of chair, retrofit or not is to be considered.

According to an embodiment of the invention, a wheelchair with seating assembly is now described with possible movements in either symmetric or asymmetric operation. It is noted that such seating assembly with different possible movements could also be applicable for other types of chairs such as for example an ergonomic chair, a vehicle chair, a design furniture chair. While referring to the seating assembly700ofFIGS.7A and7B, more in particularFIG.7A, a first movement indicated by the arrow M1is determined at the height of the backrest708of the back-support unit703. The arrow M1indicates that the backrest708can be moved forward or backward. The back-support unit703and its backrest708can be further segmented into a back left part703L.708L and a back right part703R,708R respectively.

Both inFIG.7Aas inFIG.7B, a surface or plane is outlined dividing the wheelchair in two identical halves as a left part at the left L from the surface and as a right part at the right R from the surface. Moreover, with such left and right segmentation, the back left and right parts703L,708L,703R,708R could be controlled separately and independently from each other, such that for example only the back left part703L,708L is moved in accordance with the arrow M1, or the back left part703L,708L is moved with a different grade than the back right part703R,708R, Hence, asymmetric movement is possible, and herewith described of the back parts703L,708L,703R,708R.

Particularly for healthcare or medical applications asymmetric operation of a chair or wheelchair can be very useful. In fact, independent from the invention, it occurs often in practice that the back-support unit, or the backrest in particular is adapted with additional material to make asymmetric correction, necessary for the patient, possible. Such adaptation can be done e.g. by adding an extra lateral cushioning piece on left or right upper side of the backrest, however, the same idea could also be applicable for lower back parts. With the invention, adding material is no longer needed whereas asymmetric correction or adaptation can be performed by means of installation and control of segmented parts of the seating assembly700.

Another movement of the seating assembly700going along with possible correction for improving seating comfort is determined by arrow M2as depicted inFIG.7B. In particular, pelvic correction can be done by means of a stretch band, as commonly known in the art. Such stretch band is specifically present in a wheelchair for instance at the lower back of the wheelchair, just above seat or adjacent to seat. Alternatively, and with reference to the current invention, pelvic correction is also feasible by means of a screw740, and herewith enabling the lower back722B moving forward or backward. Moreover, asymmetric movement along M2for left and right part of the lower back could be possible by independently controlling left and right screw740L,740R.

Referring back toFIG.7A, a further movement is determined with the arrow M3. Whereas the sitting722, more in particular the horizontal plane or seat722A of the seat unit702can be segmented into a front seat part722A1and a back seat part722A2, the front seat part722A1can be moved separately and independently from the back seat part722A2. The seat722A is hence divided in two parts. By means of example, these two parts relate to each other as ⅓ and ⅔ of the seat722A with a front ⅔ and a back ⅓, or as two halves of the seat722A with a front half and a back half. Other relations amongst these two parts, such as e.g. ⅖ and ⅗ are also covered with the invention. Up or lowering movement of the front seat part722A1is applicable as indicated by M3. Such up and lowering movement is for instance made possible and moreover driven by means of an actuator provided at hip joint and connected with the front seat part722A1. Furthermore, the front seat part722A1can be segmented in a left and right part722A1L,722A1R to be controlled separately and independently, such that asymmetric operation or correction in seating comfort for left and right leg can be performed. Particularly for people suffering from hemiplegia or partial paralysis e.g. because of a stroke, such asymmetric movement is very much wanted.