The present application is the U.S. national phase under § 371 of International Application No. PCT/EP2015/071206, having an international filing date of Sep. 16, 2015, which claims priority to EP Patent Application No. 14185547.8, filed Sep. 19, 2014. Each of the above-mentioned prior-filed applications is hereby expressly incorporated herein by reference in its entirety.
The present disclosure generally relates to a wheelchair and in particular to an electrically powered wheelchair arranged to enable tilt of the wheelchair seat.
Electrically powered wheelchairs are commonly fitted with a tilt mechanism which allows adjustment of the orientation of a seat frame comprising a seat part and a backrest part. Electrically powered wheelchairs may also be provided with a lift mechanism which allows adjustment of the height of the wheelchair seat. The combination of these two mechanisms can provide seat frame adjustment such as anterior tilting, i.e. forward tilting, posterior tilting, i.e. backwards tilting, and/or elevation of the seat frame. A seat occupant or caretaker may thereby set the seat position according to desire or current need of the occupant.
When the seat position is altered by the tilt mechanism and/or the lift mechanism, it may be desirable to be able to simultaneously control the position of the armrest of the wheelchair to provide optimal support for the wheelchair occupant during tilt/lift operation as well as in the resulting seat position. This is for example the case when the seat frame is being set into an anterior tilt position. During this entire motion it is advantageous to be able to maintain the armrest parallel to ground. The wheelchair occupant can then feel safe during the tilt operation because the occupant may confidently lean against the armrest, as the armrest is parallel to the ground. On the other hand, when the seat frame is tilted back, it is generally perceived to be more comfortable and safe if the armrest is perpendicular to the backrest and not parallel to the ground.
In existing electrically powered wheelchair designs the tilt mechanism and the lift mechanism have typically been separated. The linkage that controls the position of the armrest may then be coupled to a fixed point on the lift mechanism, to which fixed point the armrest adjustment relates to. In this manner, the armrest is kept parallel with ground during a tilt operation.
Today, electrically powered wheelchairs with a different design concerning the lift/tilt functionality are entering the market. These wheelchairs have a common mechanism for providing tilt/lift. A linkage of the type utilised in the separated tilt mechanism and lift mechanism design would not provide armrest adjustment functionality which, for example, is parallel to ground during tilt operation.
In view of the above, a general object of the present disclosure is to provide an electrically powered wheelchair which solves or at least mitigates the problems of the prior art.
An electrically powered wheelchair comprising a chassis; a seat frame; a seat frame tilt and lift system having a lifting member arranged to provide translational movement of the seat frame relative to the chassis, and a first arm which in cooperation with the lifting member is arranged to tilt the seat frame relative to the chassis; an armrest assembly pivotally coupled to the seat frame; and an armrest adjustment arrangement comprising a first force transmitting arrangement having four pivot points defining the vertices of a first parallelogram, which first force transmitting arrangement is pivotally coupled to the first arm via a first pivot point of the four pivot points defining the vertices of the first parallelogram, and pivotally coupled to the lifting member via a second pivot point of the four pivot points defining the vertices of the first parallelogram; and a second force transmitting arrangement having four pivot points defining the vertices of a second parallelogram, which second force transmitting arrangement is pivotally coupled to the first force transmitting arrangement via a first pivot point of the four pivot points defining the vertices of the second parallelogram, which second force transmitting arrangement is pivotally coupled to the seat frame via a second pivot point of the four pivot points defining the vertices of the second parallelogram, and which second force transmitting arrangement is pivotally coupled to the armrest assembly.
An effect which may be obtainable thereby is that the armrest position can be controlled when the seat frame is actuated by the seat frame tilt and lift system, due to the interaction between the seat frame tilt and lift system, the first force transmitting arrangement, and the second force transmitting arrangement. By means of the first force transmitting arrangement, and in particular by the pivot points formed by the first parallelogram, a pivot point is formed around which the second force transmitting arrangement and the second parallelogram is able to pivot when the seat frame tilt and lift system is operated. The armrest will therefore remain parallel to the ground during the operation of setting the seat frame in an anterior tilt position and when the seat is elevated. Furthermore, the armrest remains perpendicular to the backrest part during posterior tilt operation of the seat frame. When the backrest part is tilted back separately from the seat part, the armrest remains perpendicular to the backrest part. Thus, in general, flexible armrest position adjustment may be provided, which ensures comfort and security to the wheelchair occupant during tilt and lift operations.
According to one embodiment the first pivot point and the second pivot point of the four pivot points defining the vertices of the first parallelogram are the vertices of a first long side of the first parallelogram.
According to one embodiment the first pivot point and the second pivot point of the four pivot points defining the vertices of the first parallelogram are arranged further away from the chassis than a third pivot point and a fourth pivot point of the four pivot points defining the vertices of the first parallelogram.
According to one embodiment the second force transmitting arrangement comprises a force transmitting arm which defines a first long side of the second parallelogram, and wherein the force transmitting arm is pivotally coupled to the first force transmitting arrangement.
According to one embodiment the force transmitting arm is pivotally coupled to the first force transmitting arrangement via the first pivot point of the four pivot points defining the vertices of the second parallelogram.
According to one embodiment a third pivot point of the four pivot points defining the vertices of the second parallelogram coincides with the first pivot point of the four pivot points defining the vertices of the first parallelogram.
According to one embodiment the second pivot point and a third pivot point of the four pivot points defining the vertices of the second parallelogram are the vertices of a first long side of the second parallelogram.
According to one embodiment the first force transmitting arrangement is pivotally coupled to a front end portion of the first arm via the first pivot point of the four pivot points of the vertices defining the first parallelogram.
According to one embodiment a fourth pivot point of the four pivot points defining the vertices of the second parallelogram is translatable.
According to one embodiment the first pivot point and the fourth pivot point of the four pivot points defining the vertices of the second parallelogram are the vertices of a second long side of the second parallelogram.
According to one embodiment an axis defined by the second long side of the second parallelogram intersects an axis defined be the first arm.
According to one embodiment the second pivot point and a third pivot point of the four pivot points defining the vertices of the second parallelogram are arranged further away from the chassis than the first pivot point and the fourth pivot point of the four pivot points defining the vertices of the second parallelogram.
According to one embodiment the first force transmitting arrangement is a first linkage.
According to one embodiment the second force transmitting arrangement is a second linkage.
According to one embodiment the seat frame comprises a backrest part, and wherein the armrest assembly is pivotally coupled to the backrest part.
Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to “a/an/the element, apparatus, component, means, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, etc., unless explicitly stated otherwise.
The specific embodiments of the inventive concept will now be described, by way of example, with reference to the accompanying drawings, in which:
The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplifying embodiments are shown. The inventive concept may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. Like numbers refer to like elements throughout the description.
The seat frame tilt and lift system 9 has a combined lift/tilt mechanism. The seat frame tilt and lift system 9 may be operable by means of a motor and may, depending on the particular implementation, provide one of anterior tilt such as full standing tilt, posterior tilt, and lift, or a combination of anterior/posterior tilt and lift. In
The lifting member 9b is arranged to move rectilinearly relative to the base member 9a, along an axis A defined by the longitudinal extension of the lifting member 9a. The base member 9a may for example be arranged to receive the lifting member 9b such that the lifting member 9b may run in the base member 9a.
The lifting member 9b is arranged to move rectilinearly between a lowered position in which the lifting member 9b is retracted relative to the base member 9a, and an elevated or lifted position in which the lifting member 9b is extended relative to the base member 9a. Actuation of the lifting member 9b may for example be performed by means of the motor of the electrically powered wheelchair 1.
The seat frame tilt and lift system 9 further comprises a first arm 11, a second arm 13 and a tilt frame 15. The tilt frame 15 is arranged to support the seat frame 5. The first arm 11 is pivotally coupled to an end portion of the lifting member 9b and slidably connected to the second arm 13. The first arm 11 is furthermore pivotally coupled to the tilt frame 15 forming a tilt joint.
According to the example shown in
According to the example in
The seat frame tilt and lift system 9 will not be elucidated in more detail herein as it merely provides the setting for the herein disclosed armrest adjustment arrangement. A number of implementations of a seat frame tilt and lift system are envisioned, for example those disclosed in European Patent application EP13176357 filed by the same applicant.
The armrest adjustment arrangement 17 comprises a first force transmitting arrangement 21 and a second force transmitting arrangement 23. The first force transmitting arrangement 21 is pivotally coupled to the seat frame tilt and lift system 9 and to the second force transmitting arrangement 23. The second force transmitting arrangement 23 is pivotally coupled to the armrest assembly 19. Translational and rotational motion provided by the seat frame tilt and lift system 9 can thereby be transmitted from the seat frame tilt and lift system 9 to the armrest assembly 19 via the first force transmitting arrangement 21 and the second force transmitting arrangement 23.
The first force transmitting arrangement 21 comprises a number of members that are arranged to mechanically cooperate so as to transmit movement from the seat frame tilt and lift system 9 to the second force transmitting arrangement 23. The first force transmitting arrangement 21 has four pivot points. Each of the four pivot points is a point on respective axis about which a respective member of the first force transmitting arrangement 21 can pivot. These four pivot points 21-1 to 21-4 define the vertices of a first parallelogram P1, shown in
The first pivot point 21-1 of the pivot points defining the vertices of the first parallelogram P1 is defined by a pivot coupling between the first force transmitting arrangement 21 and the first arm 11 of the seat frame tilt and lift system 9.
According to one variation, the force transmitting arrangement 21 is a first linkage. In this variation the pivot points of the first linkage define the four pivot points that form the first parallelogram P1.
The second force transmitting arrangement 23 comprises a number of members that are arranged to mechanically cooperate so as to transmit movement from the first force transmitting arrangement 21 to the armrest assembly 19. The second force transmitting arrangement 23 has four pivot points. Each of the four pivot points is a point on a respective axis about which a respective member of the second force transmitting arrangement 23 can pivot. These four pivot points 23-1 to 23-4 define the vertices of a second parallelogram P2, shown in
According to one variation, the second force transmitting arrangement 23 is a second linkage. In this variation the pivot points of the second linkage define the four pivot points that form the second parallelogram P2.
In general, it should be noted that that each axis extending through a pivot point 21-1 to 21-4 and 23-1 to 23-4 which define the vertices of the first parallelogram P1 and the second parallelogram P2 are parallel with the wheel axes.
According to the example shown in
The first pivot point 21-1 of the pivot points defining the vertices of the first parallelogram P1 coincides with a third pivot point 23-3 of the pivot points defining the vertices of the second parallelogram P2.
According to one variation, the fourth pivot point 23-4 of the four pivot points defining the vertices of the second parallelogram P2 is translatable parallel with the direction along which the long sides of the second parallelogram P2 extend, in particular that side of the second parallelogram P2 which is closer to the chassis 3. The fourth pivot point 23-4 of the four pivot points defining the vertices of the second parallelogram P2 is thus translatable along the axis of the longitudinal extension of the force transmitting arm 25. This may for example be achieved by an extendable/retractable force transmitting arm 25, or in case the force transmitting arm is not extendable, by means of a force transmitting arm 25 having a slot in which an end of the curved member 27 can slide. One way of achieving the extendibility/retractability of the force transmitting arm 25 is to let the force transmitting arm 25 comprise two concentric tubes with different inner diameters such that one tube may move and slide within the other. By combining such an alternative with an inner spring, the extendibility can be controlled in a smooth and efficient manner. By being able to translate the fourth pivot point 23-4 of the four pivot points defining the vertices of the second parallelogram P2 in a rectilinear manner, it is possible to decouple the armrest adjustment arrangement 17 to avoid actuation of the armrest assembly 19 during posterior tilt. It should be noted that due to this translation the second parallelogram P2 becomes warped when posterior tilt is performed, as shown in
The armrest assembly 19 comprises armrests 19a and a pivot arrangement 19b that is an extension of the armrests 19a. The pivot arrangement 19b is pivotally coupled to the seat frame 5, in particular to the backrest part 5b. The pivot arrangement 19b may for example comprise journals or pivots that extend into respective openings in the backrest part 5b, or it may comprise openings into which journals or pivots extend from the backrest part 5b. Pivot functionality of the armrests 19a may thereby be obtained. The pivot arrangement 19b may further comprise pivot arms 29, each of which forms part of a respective armrest 19a.
The armrest assembly 19 further comprises an arrangement that at one end is pivotally coupled to the pivot arrangement 19b and at the other end to the second force transmitting arrangement 23. The arrangement may for example be realised by means of one or more arms 31 that are pivotally coupled to the second force transmitting arrangement 23, for example to the curved member 27, and to a respective pivot arm 29. The pivotal coupling 30 between the arm 31 and the curved member 27 is displaced relative to the second pivot point 23-2 of the four pivot points defining the vertices of the second parallelogram P2, to enable pivoting of the arm 31 about the second pivot point 23-2.
The armrest assembly 19 may according to one variation further comprise a rod 32 extending transversely, for enabling adjustment of both armrests 19a. The rod 32 extends from one lateral side of the electrically powered wheelchair 1 to the other lateral side, parallel to the wheel axes. The rod 32 has a distal end and a proximal end. The proximal end is coupled to the curved member 27 in a manner in which the second pivot point 23-2 of the four pivot points defining the vertices of the second parallelogram P2 is a point on the central axis of the rod 32. The rod 32 is arranged to rotate about its central axis simultaneously, and as a result of the second force transmitting arrangement 23 pivoting about the same axis. The distal end may be provided with a pivot member 28 fixedly arranged relative to the rod 32. An arm 31 is pivotally coupled to the pivot member 28. This arm 31 may furthermore be coupled to the pivot arrangement 19b in a similar manner as the other arm 31 to enable actuation of the armrest 19a located at the distal lateral side of the electrically powered wheelchair 1 relative to the armrest adjustment arrangement 17.
Motion of the second force transmitting arrangement 23 may thereby be transferred to the pivot arrangement 19b for controlling the position of the armrests 19a.
According to the example in
The first pivot point 21-1 and the second pivot point 21-2 of the four pivot points defining the vertices of the first parallelogram P1, shown with dashed lines in
The second pivot point 23-2 and a third pivot point 23-3 of the four pivot points defining the vertices of the second parallelogram P2 are arranged further away from the chassis 3 than the first pivot point 23-1 and the fourth pivot point 23-4 of the four pivot points defining the vertices of the second parallelogram P2. The second pivot point 23-2 and a third pivot point 23-3 of the four pivot points defining the vertices of the second parallelogram P2 are the vertices of a first long side of the second parallelogram P2.
An axis B defined by the second long side of the second parallelogram P2 intersects an axis C defined be the first arm 11. This is true for all positions that the first arm 11 and of the second parallelogram P2 can assume relative to each other.
The translation of the fourth pivot point 23-4 is illustrated in
Although the exemplified electrically powered wheelchair 1 is of front wheel drive type, it should be noted that the wheelchair could be of any wheel drive type such as midwheel drive type, back wheel drive type, four wheel drive type or six wheel drive type.
The inventive concept has mainly been described above with reference to a few examples. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the inventive concept, as defined by the appended claims.
Number | Date | Country | Kind |
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14185547 | Sep 2014 | EP | regional |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2015/071206 | 9/16/2015 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2016/042021 | 3/24/2016 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
4456086 | Wier | Jun 1984 | A |
4637652 | Bergenwall | Jan 1987 | A |
5098158 | Palarski | Mar 1992 | A |
5366036 | Perry | Nov 1994 | A |
20070085396 | Hunziker | Apr 2007 | A1 |
20090218784 | Porcheron | Sep 2009 | A1 |
20100207354 | Hunziker | Aug 2010 | A1 |
20100259085 | Lindell | Oct 2010 | A1 |
20120181832 | Lin | Jul 2012 | A1 |
20130278032 | Hunziker | Oct 2013 | A1 |
20160106607 | Lykkegaard | Apr 2016 | A1 |
Number | Date | Country |
---|---|---|
697181 | Jun 2008 | CH |
101103946 | Jan 2008 | CN |
101184460 | May 2008 | CN |
201542846 | Aug 2010 | CN |
103054674 | Apr 2013 | CN |
1859765 | Nov 2007 | EP |
200067615 | Nov 2000 | WO |
2009009913 | Jan 2009 | WO |
2009058077 | May 2009 | WO |
Entry |
---|
PCT International Search Report, PCT Application No. PCT/EP2015/071206, Int'l filing date of Sep. 16, 2015, dated Oct. 15, 2015, 4 pages. |
Search Report for Chinese Patent Application No. 2015800503639 dated Jan. 23, 2018, 2 pages. |
Number | Date | Country | |
---|---|---|---|
20180177653 A1 | Jun 2018 | US |