Tilt assembly for a powered wheelchair and a powered wheelchair comprising the same

Abstract

The present disclosure relates to a tilt assembly (1) for a powered wheelchair (15), comprising: an elongated base member (3) provided with an axial channel, a lifting member (5) configured to be received by the base member (3) and to move rectilinearly in the channel, between a retracted position and an extended position relative to the base member (3), a tilt frame (7) pivotally connected to the lifting member (5), the tilt frame (7) being configured for mounting a seat assembly (21) thereto, and an actuator arm (9) pivotally connected to the base member (3) and to the tilt frame (7), the actuator arm (9) being configured to be actuated between a retracted actuator position and a fully extended actuator position, wherein the tilt frame (7) is configured to obtain a perpendicular orientation relative to a central axis (11) of the lifting member (5) when the lifting member (5) is in the retracted position and the actuator arm is in the retracted actuator position and to be inclined relative to the central axis (11) when the lifting member (5) is in an extended position and actuator arm is in the retracted actuator position, to thereby provide a tilt functionality.

Claims

1. A tilt assembly for a powered wheelchair, comprising: an elongated base member provided with an axial channel, a motorized lifting member configured to be received by the base member and to move rectilinearly in the channel, between a retracted position and an extended position relative to the base member, a tilt frame pivotally connected directly to the motorized lifting member, the tilt frame being configured for mounting a seat assembly thereto, and an actuator arm pivotally connected directly to the base member and to the tilt frame, the actuator arm being configured to be actuated between a retracted actuator position and a fully extended actuator position, wherein the tilt frame is configured to obtain a perpendicular orientation relative to a central axis of the motorized lifting member when the motorized lifting member is in the retracted position and the actuator arm is in the retracted actuator position and to be inclined relative to the central axis when the motorized lifting member is in an extended position and the actuator arm is in the retracted actuator position, to thereby provide a tilt functionality.

2. The tilt assembly of claim 1, wherein the tilt frame is configured to obtain an inclined position relative to the central axis when the motorized lifting member is in the retracted position and the actuator arm is in an extended position.

3. The tilt assembly of claim 1, wherein the tilt frame is configured to obtain a perpendicular orientation relative to the central axis when the motorized lifting member is in a fully extended position and the actuator arm is in the fully extended actuator position.

4. The tilt assembly of claim 1, wherein the base member is configured to be immovably mounted to a chassis frame of a powered wheelchair.

5. The tilt assembly of claim 1, wherein the actuator arm has a first end which is pivotally connected to the base member and a second end which is pivotally connected to the tilt frame.

6. The tilt assembly of claim 1, wherein the tilt frame has an essentially planar surface configured for mounting a seat assembly of a powered wheelchair thereto.

7. The tilt assembly of claim 1, wherein the pivot connection between the motorized lifting member and the tilt frame is aligned with a central axis of the motorized lifting member.

8. The tilt assembly of claim 1, wherein the actuator arm is configured to provide a controlled degree of tilt per height unit of movement of the motorized lifting member.

9. A powered wheelchair comprising: a chassis frame, and a tilt assembly comprising: an elongated base member provided with an axial channel, a motorized lifting member configured to be received by the base member and to move rectilinearly in the channel, between a retracted position and an extended position relative to the base member, a tilt frame pivotally connected directly to the motorized lifting member, the tilt frame being configured for mounting a seat assembly thereto, and an actuator arm pivotally connected directly to the base member and to the tilt frame, the actuator arm being configured to be actuated between a retracted actuator position and a fully extended actuator position, wherein the tilt frame is configured to obtain a perpendicular orientation relative to a central axis of the motorized lifting member when the motorized lifting member is in the retracted position and the actuator arm is in the retracted actuator position and to be inclined relative to the central axis when the motorized lifting member is in an extended position and the actuator arm is in the retracted actuator position, to thereby provide a tilt functionality.

10. The powered wheelchair of claim 9, wherein the base member is immovably mounted to the chassis frame.

11. The powered wheelchair of claim 10, wherein the base member has a central axis which is oriented vertically when the powered wheelchair is arranged horizontally on a planar surface.

12. The powered wheelchair of claim 9, comprising a seat assembly, wherein the seat assembly is mounted to the tilt frame.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The specific embodiments of the inventive concept will now be described, by way of example, with reference to the accompanying drawings, in which:

(2) FIG. 1 schematically shows a side view of an example of tilt assembly in a default non-tilting and non-lifted position;

(3) FIG. 2 schematically shows a side view of the tilt assembly in FIG. 1 in an anterior tilt position;

(4) FIG. 3 schematically shows a side view of the tilt assembly in FIG. 1 in a posterior tilt position;

(5) FIG. 4 schematically shows a side view of the tilt assembly in FIG. 1 in a lifted position; and

(6) FIG. 5 shows a powered wheelchair comprising the tilt assembly in FIG. 1.

DETAILED DESCRIPTION

(7) 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.

(8) FIG. 1 shows an example of a tilt assembly 1 for a powered wheelchair, in a default non-tilting and non-lifted position or state. In the default non-tilting and non-lifted position of the tilt assembly 1, no tilt and no lift functionality is provided by the tilt assembly 1.

(9) The tilt assembly 1 comprises an elongated base member 3, a lifting member 5, a tilt frame 7 and an actuator arm 9.

(10) The base member 3 is configured to receive the lifting member 5. Hereto, the base member 3 is provided with an axial channel in which the lifting member 5 is configured to be received. The lifting member 5 is configured to move rectilinearly relative to the base member 3, in the axial channel, between a retracted position relative to the base member and an extended position relative to the base member 3. The lifting member 5 and the base member 3 are hence concentrically arranged. In the retracted position, the lifting member 5 is received maximally by the base member 3, as shown in FIG. 1. In this case, the lifting member 5 is not able to be received further by the base member 3. In the extended position, the lifting member 5 extends or protrudes from the base member 3 more than in the retracted position.

(11) The lifting member 5 may according to one variation be configured to be actuated between the retracted position and an extended position by means of a motor.

(12) The base member 3 may according to one variation be configured to be immovably attached or mounted to a chassis frame of a powered wheelchair. The base member 3 is in this case, when mounted to the chassis frame, immovably arranged relative to the chassis frame.

(13) The base member 3 is arranged to extend in a vertical plane when the tilt assembly 1 is mounted to a chassis frame and the powered wheelchair is placed on a horizontal support surface.

(14) The tilt frame 7 is configured to allow a seat assembly to be mounted to the tilt frame 7. The tilt frame 7 is provided with an essentially planar surface, or a planar surface, 7a to which a seat assembly may be mounted. This essentially planar or planar surface 7a is typically an upper surface of the tilt frame 7. The upper surface is a surface which faces away from the base member 3 and the lifting member 5 and which is intersected by a central axis 11 defined by the longitudinal extension of the lifting member 5.

(15) The tilt frame 7 is pivotally connected to the lifting member 5. The tilt frame 7 is hence pivotable relative to the lifting member 5 about a pivot axis formed by the pivot connection A between the tilt frame 7 and the lifting member 5. The pivot connection A allows the tilt frame 7 to be moved relative to the base member 3 when the lifting member 5 is moved between the retracted and an extended position.

(16) According to the example shown in FIG. 1, the tilt frame 7 is arranged asymmetrically relative to the central axis 11. The majority of the tilt frame 7 has an extension on one side of the central axis 11. The pivot connection B between the tilt frame 7 and the actuator arm 9 is located on that side of the central axis 11 on which the majority of the tilt frame 7 extends. The pivot connection A, which defines the pivot connection between the lifting member 5 and the tilt frame 7 is preferably arranged aligned with the central axis 11.

(17) The actuator arm 9 extends between the base member 3 and the tilt frame 7. The actuator arm 9 is pivotally connected to the tilt frame 7 and to the base member 3. The tilt frame 7 is hence pivotable relative to the actuator arm 9 about a pivot axis formed by the pivot connection B between the actuator arm 9 and the tilt frame 7. Moreover, the actuator arm 9 is pivotable relative to the base member 5 about a pivot axis formed by the pivot connection C between the actuator arm 9 and the base member 5. According to one variation, the pivot connection B forms one end of the actuator arm 9 and the pivot connection C forms the other end of the actuator arm 9.

(18) The actuator arm 9 is configured to be actuated or maneuvered between a retracted actuator position and a fully extended actuator position. The actuator arm 9 is thereby able to control the pivot position of the tilt frame 7 about the pivot connection A. The actuator arm 9 may be configured to obtain a plurality of positions between the retracted actuator position and the fully extended actuator position. The amount of extension relative to the retracted actuator position is one variable for providing tilt/lift of the tilt assembly 1. Another variable is the amount of extension/retraction of the lifting member 5. By means of the combination of positions of these two extensible/retractable components posterior tilt, anterior tilt and lift may be obtained, as will be explained in more detail below.

(19) As shown in FIG. 1, when the lifting member 5 is in the retracted position and the actuator arm 9 is in the retracted actuator position, the tilt frame 7 is arranged perpendicular to the central axis 11. In particular, the essentially planar surface 7a of the tilt frame 7 defines a plane P which is arranged perpendicular to the central axis 11 and the central axis 11 intersects the plane P.

(20) Turning to FIG. 2, the tilt assembly 1 is shown having a tilting position or state. The tilting position or state is in this case an anterior tilt position. The tilt assembly 1 is hence configured to provide forward tilt functionality when mounted to a powered wheelchair. The lifting member 5 is in the example shown in FIG. 2 in the retracted position and the actuator arm 9 is in the fully extended actuator position. Maximal anterior tilt is thereby obtained. A plurality of different anterior tilt positions of the tilt frame 7 may be obtained, depending on the degree of extension of the actuator arm 9.

(21) FIG. 3 depicts another tilt position of the tilt assembly 1. The tilting position is in this case posterior or backwards tilt. Posterior tilting can be provided by movement of the lifting member 5 from its retracted position relative to the base member 3 to an extended position relative to the base member 3 while the actuator arm 9 is not in the fully extended actuator position or in any other intermediate position which in combination with the degree of extension of the lifting member 3 provides a lift functionality.

(22) According to one example, for each extended position of the lifting member 5, the actuator arm 9 may obtain a position between the retracted actuator position and the fully extended actuator position such that the essentially planar surface 7a of the tilt frame 7 defines a plane P which is arranged perpendicular to the central axis 11 and the central axis 11 intersects the plane P. Such an intermediate position of the actuator arm 9 is in the following referred to as a lift position. When the lifting member 5 is in an extended position and the actuator arm 9 is not in a lift position, the tilt frame 7 is inclined relative to the central axis 11.

(23) Movement of the lifting member 5 towards the extended position causes the tilt frame 7 to be moved away from the base member 3. Movement of the lifting member 5 towards the retracted position causes the tilt frame 7 to be moved towards the base member 3. The pivot connection A is translated only rectilinearly when the lifting member 5 is moved between the retracted position and the extended position. In the case of posterior tilting, the pivot connection B is moved along an arc which has a radius defined by the distance between pivot connections B and C when the lifting member 5 is moved between the retracted and an extended position. This movement along the arc contributes to reducing or minimizing the change of the centre of gravity of the user during a tilt operation.

(24) The amount of posterior tilt, or the posterior tilt angle, of the tilt frame 7 of an assembled tilt assembly 1 is determined by the amount that the lifting member 5 is moved from the retracted position and the degree of extension of the actuator arm 9. The amount of posterior tilt is hence determined by the position of the pivot connection A along the central axis 11 and by the distance between the pivot connections B and C. Maximal posterior tilt is obtained when the lifting member 5 reaches its maximally extended position relative to the base member 3 and the actuator arm 9 is in the retracted actuator position.

(25) FIG. 4 shows an example when the tilt assembly 1 is in a lifted position or state. In a lifted position of the tilt frame 7, the essentially planar surface 7a of the tilt frame 7 defines a plane P which is arranged perpendicular to the central axis 11 and the central axis 11 intersects the plane P. In the example shown in FIG. 4, the lifting member 5 is in the fully extended position and the actuator arm 9 is in the fully extended actuator position. This is according to the present example the combination which provides the maximum lift of the tilt frame 7. The maximum lift may for some examples of the tilt assembly not occur when both the lifting member and the actuator arm are in their respective fully extended position, as this depends on the stroke lengths of the lifting member and of the actuator arm. In these cases full extension of the lifting member and full extension of the actuator arm may instead lead to an anterior tilt position or posterior tilt position of the tilt frame. As previously mentioned, a plurality of other lift positions may be obtained by suitable combinations of extension of the lift member 5 and the actuator arm 9.

(26) The actuator arm 9 provides a controlled tilting of the tilt frame 7. The actuator arm 9 provides a controlled degree of tilt per height unit of movement of the lifting member 5. If no actuator arm would be provided, the tilt frame would tilt uncontrollably to obtain a state of posterior tilt or anterior tilt depending on e.g. the centre of gravity and/or the weight of a seat occupant of a seat assembly mounted to the tilt frame. The maximal tilt that can be provided by the tilt assembly 1 is determined by the position of the pivot connection B along the tilt frame 7, the position of the pivot connection C along the base member 3, and on the length of the actuator arm 9.

(27) The tilt assembly 1 may according to one variation comprise a resilient member. The resilient member is in this case configured to provide damping of the tilt frame 7. The resilient member may for example be a spring, in which case the actuator arm 9 and the resilient member 13 may form a strut, or it may be a resilient bushing or a resilient sleeve attached to an end of the actuator arm 9, and which is able to expand and contract in the longitudinal direction of the actuator arm 9. The resilient member may in this case for example be made of a polymeric material.

(28) FIG. 5 shows an example of a powered wheelchair 15. The exemplified powered wheelchair 15 is a mid-wheel drive wheelchair, but could alternatively be a front-wheel drive wheelchair or a rear-wheel drive wheelchair.

(29) The powered wheelchair 15 comprises a plurality of wheels 17a-17c. In the present example there are two front caster wheels 17a, two drive wheels 17b and two rear caster wheels 17c. The powered wheelchair 11 furthermore comprises a chassis frame 19 on which at least one battery, not shown, is mounted for driving the drive wheels 17b, and the tilt assembly 1. The tilt assembly 1 is mounted to the chassis frame 19. According to the present example, the tilt assembly 1 is mounted to the chassis frame 19 in front of the at least one battery. The base member 3 is located centred between the two drive wheels 17b in a direction from one of the drive wheels 17b to the other drive wheel 17b.

(30) When the tilt assembly 1 is mounted to the chassis frame 19, the pivot connection A is located closer to the front end of the chassis frame 19 than the pivot connection B irrespective of whether the tilt assembly is in a tilting or a non-tilting position. To this end, when the tilt assembly 1 is mounted to the powered wheelchair 11, the pivot connection A is located closer to the front end of the powered wheelchair 11 than the pivot connection B.

(31) The powered wheelchair 15 furthermore comprises a seat assembly 21, comprising a seat 21a and a backrest 21b. The seat assembly 21 is mounted to the tilt frame 7. In particular, the seat assembly 21 is fixedly mounted on top of the tilt frame 7, to the essentially planar surface 7a shown in FIG. 1. The tilt assembly 1 and the seat assembly 21 form a seating system of the powered wheelchair 15.

(32) By moving the lifting member 5 and/or by maneuvering the actuator arm 9, various tilting and lifting positions of the seat assembly 21 may be provided.

(33) 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.