Lift and tilt device for electric wheelchairs

Abstract

A lift-tilt device 1 for operating the seat of an electric wheelchair. The upper beam 3 has an upper proximal end 3a and an upper distal end 3b. A first linear actuator is positioned along the upper beam 3. The first linear actuator includes a first carrier unit that travels along the upper beam 3 from a distal position towards the proximal end 3a to a proximal position, and from the proximal position to a distal position. A second linear actuator is positioned along the lower beam 5. The second linear actuator includes a second carrier unit that travels along the lower beam 5 between a first position and a second position. The main arm 7 is pivotably connected to the proximal end 3a of the upper beam 3 and to the second carrier unit. The upper arm 9 is pivotably connected to the main arm 7 and to the first carrier unit. A mounting structure 13 is fixedly positioned relative to the lower beam 5. The lower arm 11 is pivotably connected to the main arm 7 and to the mounting structure 13.

Description

Technical Field

[0001] The present disclosure generally relates to electric wheelchairs.

Background Art

[0002] An electric wheelchair (power wheelchair) may have a lift tilt function (lift and tilt functionality) to enable a user to obtain a tilt position or a lift / elevated position (elevated position) within the seat.

[0003] An example of a lift tilt device for an electric wheelchair is disclosed in Patent Document 1. The electric wheelchair includes a chassis and a lift device having a base member fixedly disposed on the chassis. The electric wheelchair further includes a lift member arranged to move linearly relative to the base member along an axis defined by the longitudinal extension of the lift member, a tilt frame, a first arm pivotally coupled to the lift member and the tilt frame, and a second arm coupled to the base member. The second arm forms a pivot connection by being pivotally coupled to the first arm. Movement of the lift member towards the extended position moves the pivot connection towards the base member, and movement of the lift member towards the retracted position moves the pivot connection away from the base member.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Due to the vertical arrangement of the base member and lift member of the lift device disclosed in Patent Document 1, if the lifting capacity is good, the seat-to-floor height becomes considerably high, or if the seat-to-floor height is low, the lifting capacity is impaired. In the latter case, the tilt angle also becomes smaller.

[0006] A general objective of this disclosure is to provide a lift-tilt device for electric wheelchairs that solves or at least mitigates the problems of the prior art. [Means for solving the problem]

[0007] Accordingly, according to a first aspect of the present disclosure, a lift-tilt device for operating the seat of an electric wheelchair is disclosed. The lift-tilt device comprises an upper beam having a proximal end and a distal end; a first linear actuator disposed along the upper beam, comprising a first carrier unit configured to travel along the upper beam from a distal position toward the proximal end to a proximal position, and from the proximal position to a distal position; a lower beam; a second linear actuator disposed along the lower beam, comprising a second carrier unit configured to travel along the lower beam between a first position and a second position; a main arm pivotably connected to the proximal end of the upper beam and the second carrier unit; an upper arm pivotably connected to the main arm and the first carrier unit; a mounting structure fixedly disposed relative to the lower beam; and a lower arm pivotably connected to the main arm and the mounting structure.

[0008] A lift-tilt device is realized that allows for a low seat-to-floor height regardless of the lifting capacity, through the configuration of two linear actuators positioned along each beam, and a main arm, an upper arm, and a lower arm. Therefore, it is possible to provide both a low minimum seat-to-floor height and a high maximum seat-to-floor height.

[0009] According to one embodiment, when the first carrier unit is located at the distal position and the second carrier unit is located at the first position, the lift-tilt device is in a folded state. According to one embodiment, in the folded state, the upper beam is arranged parallel to the lower beam.

[0010] According to one embodiment, the lift-tilt device is in the lifted state when the first carrier unit is located closer to a position proximal to the folded state, and the second carrier unit is located closer to the second position than the folded state.

[0011] According to one embodiment, in the lifted state, the upper beam is parallel to the lower beam. According to one embodiment, the mounting structure is connected to the second end of the lower beam. The second carrier unit is configured to reach the second position by traveling along the lower beam from the first position toward the second end.

[0012] According to one embodiment, when the first carrier unit is located at the distal position and the second carrier unit is located at the second position, the lift-tilt device is in a tilted state. One embodiment includes a first electric motor configured to drive a first linear actuator and a second electric motor configured to drive a second linear actuator.

[0013] According to one embodiment, the lower beam is configured to be fixedly attached to the chassis of the electric wheelchair. According to one embodiment, the upper beam and the lower beam are included in the median plane of the lift-tilt device.

[0014] According to one embodiment, in cross-section, each of the first and second carrier units has a plurality of projections along its outer circumference. Each of the upper and lower beams has a plurality of flat support surfaces configured to support one of each projections of the first and second carrier units, and a plurality of sliding bearings. Each sliding bearing is positioned between each projection and the support surface to facilitate the axial movement of the first and second carrier units relative to each beam.

[0015] According to one embodiment, for each of the first and second carrier units, the protrusions are two upper lateral protrusions and two lower lateral protrusions. Each of the upper beam and lower beam has four flat support surfaces configured to support one of each of the lateral protrusions.

[0016] The flat support surface allows the fitting between the upper / lower beam and the first / second support unit to be less dependent on tolerances, thus facilitating axial movement between these components.

[0017] The bearing may be constructed from a polymer material. The sliding bearings may be fixedly mounted to the respective first and second carrier units. According to one embodiment, each support surface forms part of the respective grooves within the upper and lower beams. Each lateral projection is configured to travel within the groove.

[0018] According to one embodiment, each of the first and second carrier units comprises a central carrier unit body and two lateral wing members. Each lateral wing member is attached to the respective side of the central carrier unit body.

[0019] According to one embodiment, each lateral wing member includes an upper protrusion and a lower protrusion. The profiled inner surfaces of the upper beam and the lower beam include a plurality of shoulders. Each shoulder is arranged to guide one of each of the upper protrusion and the lower protrusion.

[0020] One embodiment includes a plurality of sliding bearings. Each sliding bearing is provided between each shoulder and one of the upper protrusion or the lower protrusion. According to one embodiment, the upper beam has at least one open slot for enabling a pivotal connection between the first carrier unit and the upper arm. The lower beam has at least one open slot for enabling a pivotal connection between the second carrier unit and the main arm.

[0021] According to one embodiment, the upper beam includes at least one flexible curtain arranged to cover one of each of the at least one open slot of the upper beam. The lower beam includes at least one flexible curtain arranged to cover one of each of the at least one open slot of the lower beam.

[0022] This enables the interiors of the upper and lower beams to be protected from dirt. For example, the first and second linear actuators can be protected from dirt. According to one embodiment, each curtain is configured to include silicone.

[0023] According to one embodiment, the first linear actuator is a first screw-type actuator including a first rotatable screw, and the first carrier unit is configured to travel along the upper beam. The second linear actuator is a second screw-type actuator including a second rotatable screw, and the second carrier unit is configured to travel along the lower beam.

[0024] The first screw-type actuator may be, for example, a lead screw-type actuator or a ball screw-type actuator. The second screw-type actuator may be, for example, a lead screw-type actuator or a ball screw-type actuator.

[0025] Alternatively, the first linear actuator may be a hydraulic actuator or a pneumatic actuator. Alternatively, the second linear actuator may be a hydraulic actuator or a pneumatic actuator.

[0026] According to one embodiment, the first linear actuator is disposed inside the upper beam, and the second linear actuator is disposed inside the lower beam. According to one embodiment, each of the upper beam and the lower beam has one of the following structures, that is, is integrally formed and has a rectangular cross-sectional shape, is formed from two U-shaped beams facing each other, or is formed from one U-shaped beam.

[0027] According to a second aspect of the present disclosure, an electric wheelchair including the lift tilt device of the first aspect is provided. One embodiment includes a wheelchair chassis, and the mounting structure is integrated with the wheelchair chassis or attached to the wheelchair chassis. The lower beam is integrated with the wheelchair chassis or attached to the upper side surface (top side, upper surface) of the wheelchair chassis.

[0028] According to one example, the upper beam and the lower beam are included in the center plane of the electric wheelchair. According to one example, at least one of the upper beam and the lower beam is included in the center plane of the electric wheelchair.

[0029] According to one example, the upper beam and the lower beam are disposed on each side of the center plane of the electric wheelchair. The electric wheelchair may, in one example, be equipped with a plurality of lift-tilt devices of the first embodiment, such as two lift-tilt devices of the first embodiment. The two lift-tilt devices may be arranged symmetrically with respect to the midline plane of the electric wheelchair, that is, one on each side of the midline plane and at the same distance from the midline plane. The plurality of lift-tilt devices may be configured to operate in parallel with each other.

[0030] A third aspect of the present disclosure provides a beam structure for a lift-tilt device of an electric wheelchair. The beam structure comprises a beam, a linear actuator disposed inside the beam, and a plurality of sliding bearings. The linear actuator comprises a carrier unit configured to travel along the beam. In cross-section, the carrier unit has a plurality of projections along its outer circumference. The beam has a corresponding number of flat support surfaces configured to support one of each projection. The sliding bearings are disposed between each projection and the support surface to facilitate the axial movement of the first and second carrier units relative to each beam.

[0031] Each support surface may form part of each groove within the beam. Each projection is configured to travel within its groove. The protrusions may be distributed in cross-section along the outer circumference of the carrier unit, either in the circumferential or tangential direction of the carrier unit.

[0032] According to one example of each beam, the projection may comprise two upper lateral projections and two lower lateral projections. The beam has four flat support surfaces configured to support one of each of the lateral projections.

[0033] The beam may be the upper or lower beam of the lift-tilt device. The beam may have at least one open slot for connecting the carrier unit to an arm such as an upper arm or main arm.

[0034] The beam may include a flexible curtain configured to cover at least one open slot. The curtain may include upper and lower curtain members that extend parallel to the opening slot. The upper and lower curtain members are in contact with each other and are arranged to close the opening slot.

[0035] The curtain may be constructed, for example, by incorporating silicone. The linear actuator may also be a screw-type actuator equipped with a rotatable screw. The carrier unit is configured to travel along the rotatable screw.

[0036] A fourth aspect of the present disclosure provides a lift-tilt device for operating the seat of an electric wheelchair. The lift-tilt device comprises a lower beam; a linear actuator disposed along the lower beam and having a carrier unit configured to travel along the lower beam between a first position and a second position; a main arm pivotably connected to the carrier unit; a mounting structure fixedly disposed with respect to the lower beam; and a lower arm pivotably connected to the main arm and the mounting structure.

[0037] One embodiment includes an electric motor configured to drive a linear actuator. According to one embodiment, the lower beam is configured to be fixedly attached to the chassis of the electric wheelchair.

[0038] According to one embodiment, the lower beam is included in the midline plane of the lift-tilt device. According to one embodiment, in cross-section, the carrier unit has a plurality of protrusions along its outer circumference. The lower beam has a plurality of flat support surfaces configured to support one of each of the protrusions of the carrier unit, and a plurality of sliding bearings. Each sliding bearing is positioned between each protrusion and a support surface to facilitate the axial movement of the carrier unit relative to the lower beam.

[0039] According to one embodiment, the projection consists of two upper lateral projections and two lower lateral projections. The lower beam has four flat support surfaces configured to support one of each of the lateral projections.

[0040] According to one embodiment, each support surface forms a portion of the respective groove of the lower beam. Each lateral projection is configured to travel within the groove. According to one embodiment, the carrier unit comprises a carrier unit body and two lateral wing members. Each lateral wing member is attached to the respective side of the carrier unit body.

[0041] According to one embodiment, each lateral wing member comprises an upper projection and a lower projection. The profiled inner surface of the lower beam comprises a plurality of shoulders. Each shoulder is positioned to guide one of the upper projections and one of the lower projections.

[0042] One embodiment comprises a plurality of sliding bearings. Each sliding bearing is provided between its respective shoulder and one of the upper or lower projections. According to one embodiment, the lower beam has at least one open slot to allow a pivot connection between the carrier unit and the main arm.

[0043] According to one embodiment, the lower beam includes at least one flexible curtain positioned to cover one of each of the at least one open slots of the lower beam. According to one embodiment, each curtain is made of silicone.

[0044] According to one embodiment, the linear actuator is a screw-type actuator equipped with a rotatable screw, and the carrier unit is configured to travel along the lower beam.

[0045] According to one embodiment, the linear actuator is located inside the lower beam. According to one embodiment, the lower beam has one of the following structures: that is, it is integrally formed and has a rectangular cross-sectional shape, or it is formed from two U-shaped beams facing each other, or it is formed from one U-shaped beam.

[0046] According to a fifth aspect of this disclosure, an electric wheelchair is provided that is equipped with a lift-tilt device according to a fourth aspect. In general, all terms used in the claims should be interpreted according to their ordinary meanings in the art unless expressly defined otherwise herein. All references to “a / an / the” elements, apparatus, components, means, etc. should be expressly interpreted as referring to at least one instance of such elements, apparatus, components, means, etc., unless expressly stated otherwise.

[0047] Specific embodiments of the concept of the present invention are described herein by example with reference to the following appended drawings. [Brief explanation of the drawing]

[0048] [Figure 1] A perspective view of an example of a lift-tilt device. [Figure 2] Perspective view of the lift-tilt device with the upper and lower beams removed. [Figure 3] This shows the lift-tilt device in its folded state. [Figure 4] This shows a lift-tilt device in the lifted position. [Figure 5] This shows a lift-tilt device in a tilted position. [Figure 6] Another example of a lift-tilt device in a folded state is shown. [Figure 7] Figure 6 shows the lift-tilt device in the upright or raised position. [Figure 8] Perspective views of the upper and lower beams of the lift-tilt device in Figure 6. [Figure 9]Perspective view of the upper / lower beams, first / second carrier units, and side curtains of the lift-tilt device shown in Figure 6. [Figure 10] End view of the apparatus shown in Figure 9. [Figure 11] This shows an electric wheelchair equipped with a lift and tilt device. [Figure 12] An oblique view of an example of a tilt device. [Figure 13] A perspective view showing another example of the upper / lower beams. [Figure 14] Figure 13 shows cross-sections of the upper and lower beams. [Modes for carrying out the invention]

[0049] The concept of the present invention is fully described below with reference to the accompanying drawings illustrating exemplary embodiments. However, the concept of the present invention may be embodied in many different forms and should not be construed as being limited to the embodiments described herein. Rather, these embodiments are provided as examples so that this disclosure is thorough and complete and fully conveys the scope of the concept of the present invention to those skilled in the art. Throughout the description, similar numbers refer to similar elements.

[0050] Figure 1 shows an example of a lift-tilt device 1. The lift-tilt device 1 is configured to lift and tilt the seat of an electric wheelchair. In Figure 1, the lift-tilt device 1 is set to a somewhat upright position with a slight forward or forward tilt.

[0051] The lift-tilt device 1 comprises an upper beam 3 and a lower beam 5. The upper beam 3 and lower beam 5 may be, for example, extruded metal beams. The metal may be, for example, aluminum or an aluminum alloy, or a composite material. Other materials, including but not limited to polymers, are also intended.

[0052] The lift-tilt device 1 includes a main arm 7 that extends between the upper beam 3 and the lower beam 5. The upper beam 3 has an upper proximal end 3a as a proximal end and an upper distal end 3b as a distal end. The main arm 7 is pivotably connected to the upper beam 3. The main arm 7 may have a first main arm end 7a that is pivotably connected to the upper proximal end 3a of the upper beam 3.

[0053] The lower beam 5 has a lower first end 5a as the first end and a lower second end 5b as the second end. The lower first end 5a and the lower second end 5b are axially opposite ends of the lower beam 5.

[0054] The main arm 7 is positioned to move axially along the longitudinal axis A of the lower beam 5. The main arm 7 may have a second main arm end 7b configured to move axially along the lower beam 5.

[0055] The first main arm end 7a of the main arm 7 may be positioned at an angle to the main body 7c of the main arm 7. The first main arm end 7a of the main arm 7 may be positioned at an upward angle to the main body 7c.

[0056] The lift-tilt device 1 includes an upper arm 9. The upper arm 9 is pivotably connected to the main arm 7. The upper arm 9 may have a first upper arm end 9a that is pivotally connected to the main arm 7.

[0057] The upper arm 9 is positioned to move axially along the longitudinal axis B of the upper beam 3. The upper arm 9 may have a second upper arm end 9b configured to move axially along the upper beam 3.

[0058] The lift-tilt device 1 comprises a lower arm 11 and a mounting structure 13. The mounting structure 13 is configured to be attached to a wheelchair chassis. The mounting structure 13 may include screw or bolt holes 13a for assembling the mounting structure 13 to the wheelchair chassis. The mounting structure 13 may be, for example, a mounting plate.

[0059] If the mounting structure 13 is a mounting plate, the mounting plate may be positioned perpendicular to the longitudinal axis A of the lower beam 5, at an angle, or parallel to the longitudinal axis A.

[0060] The lower arm 11 is pivotably connected to the mounting structure 13. The lower arm 11 may have a first lower arm end 11a (Figure 1) that is pivotally connected to the mounting structure 13. The lower arm 11 is pivotably connected to the main arm 7. The lower arm 11 may have a second lower arm end 11b (Figure 1) that is pivotally connected to the main arm 7.

[0061] The lower arm 11 may be angled. The lower arm 11 may have, for example, an L-shape, or be substantially L-shaped. The lower arm 11 extends from the main arm 7 and may be angled toward the mounting structure 13.

[0062] The lift-tilt device 1 may include two upper arms 9 and two lower arms 11. The lift-tilt device 1 may also include two spaced-apart main arms 7. The two upper arms 9 may be connected to one of each of the main arms 7. The two lower arms 11 may be connected to one of each of the main arms 7.

[0063] Figure 2 shows a perspective view of the lift-tilt device 1, where the upper beam 3 and lower beam 5 have been removed to expose the internal components of the lift-tilt device 1. The lift-tilt device 1 includes a first linear actuator (15, Figure 2), which is exemplified and referred to below as the first screw actuator 15. The first screw actuator 15 is located within the upper beam 3. The first screw actuator 15 includes a first rotatable screw 15a that extends coaxially with the longitudinal axis B of the upper beam 3. The first rotatable screw 15a may extend from the upper proximal end 3a to the upper distal end 3b of the upper beam 3.

[0064] The first screw actuator 15 comprises a first carrier unit 15b. The first carrier unit 15b may be, for example, a thread or a carriage. The first carrier unit 15b is configured to travel along the first rotatable screw 15a as the first rotatable screw 15a rotates. Thus, when the first rotatable screw 15a is rotated in a first direction, the first carrier unit 15b may be positioned to move toward the upper proximal end 3a, and when the first rotatable screw 15a is rotated in a second direction opposite to the first direction, the first carrier unit 15b may be positioned to move toward the upper distal end 3b. The first carrier unit 15b has a threaded interior. The threaded interior may be formed, for example, by the inner surface of a through-opening, or it may be in the form of one or more nuts fixedly positioned inside the body of the first carrier unit 15b, the nuts being positioned around the first rotatable screw 15a.

[0065] The first carrier unit 15b is configured to move between an upper proximal position 19a and an upper distal position 19b by the rotation of the first rotatable screw 15a. The first carrier unit 15b has a through-opening that extends along the longitudinal axis B of the upper beam 3. The first rotatable screw 15a runs through (extends through) the through-opening of the first carrier unit 15b. The through-opening may be provided with threads to allow interaction with the first rotatable screw 15a.

[0066] The lift-tilt device 1 includes a first motor 17 (Figure 2). The first motor 17 may be an electric motor. The first motor 17 is configured to drive a first rotatable screw 15a. The first motor 17 is thus configured to cause rotation of the first rotatable screw 15a in a first direction and a second direction. The first motor 17 may be located at the end of the upper beam 3, for example, at the upper distal end 3b.

[0067] The second upper arm end 9b (Figure 1) of the upper arm 9 is connected to the first carrier unit 15b. Therefore, the upper arm 9 is operated by the movement of the first carrier unit 15b along the upper beam 3.

[0068] The lift-tilt device 1 includes a second linear actuator (21, Figure 2), which is exemplified and referred to below as the second screw actuator 21. The second screw actuator 21 is located on the lower beam 5 (Figure 1). The second screw actuator 21 includes a second rotatable screw 21a that extends coaxially with the longitudinal axis A of the lower beam 5. The second rotatable screw 21a may extend from the lower first end 5a to the lower second end 5b of the lower beam 5.

[0069] The second screw actuator 21 includes a second carrier unit 21b (Figure 2). The second carrier unit 21b may be, for example, a thread or a carriage. The second carrier unit 21b is configured to travel along the second rotatable screw 21a as the second rotatable screw 21a rotates. Therefore, when the second rotatable screw 21a is rotated in one direction, the second carrier unit 21b may be positioned to move toward the lower first end 5a, or when the second rotatable screw 21a is rotated in the other direction, the second carrier unit 21b may be positioned to move toward the lower second end 5b.

[0070] The second carrier unit 21b is configured to move between the lower first position 23a and the lower second position 23b by the rotation of the second rotatable screw 21a. The second carrier unit 21b has a through-opening that extends along the longitudinal axis A of the lower beam 5. The second rotatable screw 21a travels through (extends through) the through-opening of the second carrier unit 21b. The through-opening may be provided with threads to allow interaction with the second rotatable screw 21a.

[0071] The lift-tilt device 1 includes a second motor 25 (Figure 2). The second motor 25 may be an electric motor. The second motor 25 is configured to drive the second rotatable screw 21a. The second motor 25 is thus configured to rotate the second rotatable screw 21a in both rotational directions. The second motor 25 may be located at the end of the lower beam 5, for example, at the lower second end 5b or the lower first end 5a.

[0072] The second main arm end 7b of the main arm 7 (Figure 1) is connected to the second carrier unit 21b. Therefore, the main arm 7 is operated by the movement of the second carrier unit 21b along the lower beam 5.

[0073] The upper beam 3 may include a first internal support structure. The first carrier unit 15b may have a corresponding first engagement structure configured to engage with the first internal support structure in order to maintain the first carrier unit 15b in a radial position fixed with respect to the radial direction of the longitudinal axis B of the upper beam 3, and in a tangential position fixed with respect to the longitudinal axis B. Thus, the first carrier unit 15b is rotationally locked with respect to the upper beam 3.

[0074] For example, the first internal support structure may be formed in the cross-section of the upper beam 3 by the profiled inner surface of the upper beam 3. The first engagement structure may have an external contour that conforms to the shape of the profiled inner surface of the upper beam 3.

[0075] The lower beam 5 may include a second internal support structure. The second carrier unit 21b may have a corresponding second engaging structure configured to engage with the second internal support structure in order to maintain the second carrier unit 21b in a radial position fixed with respect to the radial direction of the longitudinal axis A of the lower beam 5, and in a tangential position fixed with respect to the longitudinal axis A. Thus, the second carrier unit 21b is rotationally locked with respect to the lower beam 5.

[0076] The second internal support structure may be formed, for example, by the contoured inner surface of the lower beam 5 in the cross-section of the lower beam 5. The second engagement structure may have an external contour that conforms to the shape of the contoured inner surface of the lower beam 5.

[0077] Figure 3 shows the lift-tilt device 1 in its folded state. In the folded state, the first carrier unit 15b is located at the upper distal position 19b (Figure 2), and the second carrier unit 21b is located at the lower first position 23a (Figure 2). In this case, the upper beam 3 and the lower beam 5 are arranged in parallel. Therefore, the two longitudinal axes A and B are parallel to each other. When in use, the upper beam 3 is positioned above the lower beam 5. Furthermore, the main arm 7 is positioned parallel to both the upper beam 3 and the lower beam 5. The main arm 7 can partially receive (accommodate) the lower beam 5, as shown in Figure 3.

[0078] Figure 4 shows the lift-tilt device 1 in a fully lifted or raised state. In this case, the first carrier unit 15b is closer to the upper proximal position 19a than to the upper distal position 19b (Figure 2), and the second carrier unit 21b is located at the lower second position 23b. The upper beam 3 and the lower beam 5 are arranged parallel to each other. Thus, the longitudinal axes A and B are arranged parallel to each other when the lift-tilt device 1 is in the lifted state. By moving the first carrier unit 15b further closer to the upper proximal position 19a, the lift-tilt device 1 can be set to a significant forward tilt position, although not shown. Thereafter, when the upper beam 3 is in a significant forward tilt position, for example, 45 to 90 degrees with respect to the horizontal plane, the sheet attached to the upper beam 3 can be positioned in a near-vertical orientation, resulting in the user being in a substantially upright position. By setting the first carrier unit 15b and the second carrier unit 21b in appropriate positions along the upper beam 3 and lower beam 5, respectively, the lift-tilt device 1 can be set to a lower lift state or an elevated state than the full lift state shown in Figure 4.

[0079] In Figure 5, the lift-tilt device 1 is shown in the rearward tilt position. The rearward tilt position provides the rearward tilt function when the lift-tilt device 1 is mounted on the wheelchair chassis.

[0080] In the tilted position, the first support unit 15b is located at the upper distal position 19b (Figure 2), and the second support unit 21b is located at the lower second position 23b. In this case, the upper beam 3 is angled with respect to the lower beam 5. In this case, the longitudinal axis B of the upper beam 3 and the longitudinal axis A of the lower beam 5 are contained within their respective intersecting planes. The main arm 7 is positioned parallel to the upper beam 3.

[0081] During production, one of several possible openings 8 present in the main arm 7 may be selected for mounting the upper arm 9 to the main arm 7. Therefore, the length of the upper arm 9 used may be selected during manufacturing based on the location of the opening 8 to which the upper arm 9 is mounted. The selected opening 8 is based, for example, on the user's weight and size. The opening 8 may or may not be present in any of the examples disclosed herein.

[0082] Figure 6 shows another example of a lift-tilt device. Lift-tilt device 1' is similar to lift-tilt device 1 described above. However, the arms, such as the main arm 7' and the lower arm 11', have somewhat different designs. For example, the main arm 7' has a wider first main arm end 7a'. Furthermore, the support structure 13' has several sets of two openings 27 for attaching the lower arm 11' to the support structure 13'. During production, several sizes of lower arms 11' can be selected for the lift-tilt device 1' to be built, for example, based on the user's weight and size, and it is possible to use an appropriate set of openings 27 for attaching the lower arm 11' to the support structure 13'. Furthermore, lift-tilt device 1' may include an adapter plate 29 attached to the main arm 7'. The adapter plate 29 provides several sets of openings for attaching the lower arm 11' to the main arm 7', for example, based on the user's size and weight.

[0083] Figure 7 shows the lift-tilt device 1' in its fully lifted, i.e., raised, position. Both the lift-tilt devices 1 and 1' may have several openings in the main arms 7 and 7' for attaching the upper arms 9 and 9' to the main arms 7 and 7'. The position of the openings selected for attaching the upper arms 9 and 9' to the main arms 7 and 7' determines the force and / or velocity at which the upper arms 9 and 9' are allowed to move when the lift-tilt devices 1 and 1' change their state. The selection of positions may also be based on the user's size and / or weight.

[0084] Figure 8 shows an example of one of the upper beam 3' and lower beam 5' of a lift-tilt device 1'. Beams 3' and 5' may be extruded metal contour forms made from, for example, aluminum or an aluminum alloy, or a composite material. Other materials, including but not limited to polymers, are also considered. During production, the lengths of beams 3' and 5' may be selected based on the intended user size. For example, there may be a number of predetermined lengths for which beams 3' and 5' can be cut at the factory based on the intended user size.

[0085] Beams 3' and 5' are hollow and have a contoured inner surface. The contoured inner surface has four grooves 30 that extend in the axial direction. In the cross-section of beams 3' and 5', the grooves 30 may be located at each corner of the contoured inner surface. Other modifications are also conceivable; for example, two grooves may be centered at the top and bottom, and two grooves may be located on the lateral sides of beams 3' and 5'. According to some examples, there may be fewer than four grooves, e.g., three grooves, or more than four grooves. Each groove 30 has a flat support surface 32 (Figure 8).

[0086] Beams 3′ and 5′ have an outer surface that extends through the walls of beams 3′ and 5′ and has at least one open slot 34 that opens into the interior of beams 3′ and 5′. The open slot 34 extends along the longitudinal axis of beams 3′ and 5′. In one example, beams 3′ and 5′ have two open slots 34 located on each of their lateral sides. Alternatively, beams 3′ and 5′ may have two slots, for example, on opposing lower and upper sides, or a single slot located on the lower or upper side of beams 3′ and 5′.

[0087] Figure 9 shows beams 3' and 5' having corresponding first / second carrier units 15b' and 21b' positioned inside beams 3' and 5'. The carrier units 15b' and 21b' have outer contours that conform to the contoured inner surface shape of beams 3' and 5', for example, according to variations in the shape of the inner surface of the beam as described above.

[0088] The carrier units 15b' and 21b' are equipped with a plurality of protrusions 35a to 35b. In the example shown in Figure 9, the protrusions 35a to 35b are two upper lateral protrusions (or upper wings) 35a and two lower lateral protrusions (or lower wings) 35b. The upper lateral protrusions 35a extend toward both sides of the beams 3' and 5'. The lower lateral protrusions 35b extend toward both sides of the beams 3' and 5'.

[0089] The two upper lateral projections 35a run (extend) through one of each of the two upper grooves 30 and are positioned to rest on the respective support surfaces 32 (Figure 8) of these grooves 30. The two lower lateral projections 35b run (extend) through one of each of the two lower grooves 30 and are positioned to rest on the respective support surfaces 32 of the two lower grooves 30.

[0090] The carrier units 15b' and 21b' are equipped with a plurality of sliding bearings 37, as shown in Figure 10, a cross-sectional view of the beams 3' and 5'. Each sliding bearing 37 is positioned between its respective lateral projections 35a and 35b and the support surface 32, thereby facilitating the axial movement of the carrier units 15b' and 21b' relative to the beams 3' and 5'.

[0091] The sliding bearing 37 (Figure 10) may be attached to the carrier units 15b' and 21b' by projections of the sliding bearing 37 that extend into corresponding openings of the lateral projections 35a and 35b.

[0092] Returning to Figure 9, the beams 3', 5' are equipped with one or more flexible curtains, which are curtains 31. Each curtain 31 is positioned to cover one of the open slots 34 shown in Figure 8. Each curtain 31 may comprise a first curtain member 31a and a second curtain member 31b extending parallel to the open slots 34. The first and second curtain members 31a, 31b are in direct contact with each other and are positioned to close the open slots 34, thus protecting the interior of the beams 3', 5' from dirt and dust. The upper arm 9' and lower arm 11' are connected to the carrier units 15b', 21b' via the open slots 34. The first and second curtain members 31a, 31b are thus separated along the length of the beams 3', 5' at the connection points between the carrier units 15b', 21b' and the upper arm 9', 11', but are in contact elsewhere along the extension of the curtains 31. It should be noted that the examples disclosed in Figures 1 to 5 also have the same solution using curtains 31. Each curtain 31 may be made of, for example, silicone.

[0093] Figure 11 schematically shows an example of an electric wheelchair 39 equipped with lift-tilt devices 1, 1'. The lift-tilt devices 1, 1' are highlighted with a more prominent contour than the rest of the electric wheelchair 39 to indicate their position.

[0094] The electric wheelchair exemplified is a front-wheel drive wheelchair, but alternatively, any other drive configuration, such as a mid-wheel drive or rear-wheel drive wheelchair, may be used. The electric wheelchair 39 comprises a wheelchair chassis 41. Lift-tilt devices 1, 1' are mounted on the wheelchair chassis 41. Mounting structures 13, 13' may be mounted, for example, to the front or top of the wheelchair chassis 41. In the disclosed embodiment, beams 3, 3', 5, 5' are located on the top of the wheelchair chassis 41. Alternatively, the lower beams 5, 5' may be integrated with the wheelchair chassis 41 or may be fully or partially inserted into the top of the wheelchair chassis 41. Mounting structures 13, 13' may, according to one example, be integrated with the wheelchair chassis 41.

[0095] The electric wheelchair 39 also includes a seat 43. The seat 43 is attached to the lift-tilt devices 1, 1' such that the position of the seat 43 changes in correspondence when the lift-tilt devices 1, 1' are operated between different states. Thus, the seat 43 can be raised / up or tilted backward or forward depending on the state of the lift-tilt devices 1, 1'.

[0096] Figure 12 shows an example of a tilt device 45 for an electric wheelchair. The tilt device 45 is similar to the lift-tilt devices 1 and 1' described above, but has only a single beam, i.e., only the lower beam 5'', and no upper arm. The tilt device 45 provides only a tilt function. When the main arm 7'' is moved along the lower beam 5'' toward the lower second position 23b, the main arm 7'' is tilted as shown in Figure 12. When the tilt device 45 is installed on an electric wheelchair, it results in a tilt of the seat. When the main arm 7'' is moved to the opposite position along the lower beam 5'', the main arm 7'' is set parallel to the longitudinal axis of the lower beam 5''. When the tilt device 45 is installed on an electric wheelchair, it results in a flat / horizontal position of the seat.

[0097] The upper and / or lower beams may have a U-shape, for example, instead of having a circumferentially closed portion as illustrated in the figure. They may be formed from two U-shaped beam members facing each other, or they may have an L-shape or an I-shape.

[0098] Figure 13 shows a perspective view of another example of an upper beam 3′′′ and a lower beam 5′′′ similar to the beams described above. The upper / lower beams 3′′′ and 5′′′ may be included in any tilt-lift apparatus according to any example described herein. The beams 3′′′ and 5′′′ may be extruded metal contour forms made from, for example, aluminum or an aluminum alloy, or a composite material. Other materials, including but not limited to polymers, are also considered.

[0099] Beams 3′′′ and 5′′′ are hollow and have contoured inner surfaces. Referring to Figure 14, the carrier units 15b′′′ and 21b′′′ comprise a carrier unit body 47 and two lateral wing members 46. The carrier unit body 47 may have through-openings 49 in the longitudinal axis direction of the beams 3′′′ and 5′′′. The through-openings 49 are configured to receive a first or second rotatable screw 15a or 21a. The inner surface of the through-openings 49 is arranged to cooperate with the first or second rotatable screw 15a or 21a. Thus, when the first or second rotatable screw 15a or 21a is rotated, the carrier units 15b′′′ and 21b′′′ are moved along the beams 3′′′ and 5′′′.

[0100] Each lateral wing member 46 is attached to the carrier unit body 47. In the cross-sections of the carrier units 15b′′′ and 21b′′′, the lateral wing members 46 may be attached to each side of the carrier unit body 47. The lateral wing members 46 may be attached to the carrier unit body 47 by, for example, screws, bolts, press-fitting, and / or welding. Alternatively, the lateral wing members 46 and the central carrier body may be formed from a single part, i.e., the lateral wing members 46 and the central carrier body may form a single body.

[0101] Each lateral wing member 46 may include an upper projection (or upper flange) 51a and a lower projection (or lower flange) 51b. The contoured inner surfaces of beams 3′′′ and 5′′′ are provided with a plurality of shoulder portions 53, each positioned to guide the respective protrusions 51a and 51b. The number of shoulder portions 53 may be equal to the number of protrusions 51a and 51b. Each protrusion 51a and 51b is positioned to slide along one of the shoulder portions 53.

[0102] This configuration, in which the carrier units 15b′′′ and 21b′′′ are assembled from several components instead of being integrated, and the beams 3′′′ and 5′′′ have shoulders 53 instead of grooves, facilitates the production and assembly of the beams 3′′′ and 5′′′ with respect to manufacturing tolerances.

[0103] A sliding bearing 37'''' is provided between each shoulder portion 53 and each protrusion 51a, 51b. Each sliding bearing 37'''' is positioned between each protrusion 51a, 51b and the shoulder portion 53, thereby facilitating the longitudinal axial movement of the carrier units 15b'''', 21b'''' along the beams 3'''', 5''''.

[0104] The carrier units 15b′′′ and 21b′′′ may include mounting members 55. Each mounting member 55 may extend from one of each of the lateral wing members 46 through the respective open slots of the beams 3′′′ and 5′′′. The second upper arm end 9b of each upper arm 9 (Figure 1) may be pivotably connected to one of each of the mounting members 55.

[0105] In any variation of the upper beams 3, 3′, 3′′′ disclosed herein, instead of having two lateral open slots, the beams 3, 3′, 3′′′ may have two open slots located beneath each lateral side of the beams 3, 3′, 3′′′ for connecting two upper arms 9 to the carrier units 15b, 15b′, 15b′′′. Alternatively, there may be a single slot beneath the beams 3, 3′, 3′′′ for connecting a single upper arm 9 to the carrier units 15b, 15b′, 15b′′′. The concept of the present invention has been described above primarily with reference to several examples. However, other embodiments not disclosed above are equally possible within the scope of the concept of the present invention, as defined by the appended claims, so as can be facilitated and understood by those skilled in the art.

Claims

1. A lift-tilt device (1;1') for operating the seat (43) of an electric wheelchair (39), wherein the lift-tilt device (1;1') is An upper beam (3; 3'; 3''') having a proximal end (3a) and a distal end (3b), A first linear actuator (15) is arranged along the upper beam (3;3';3'''), and comprises a first carrier unit (15b;15b';15''') configured to travel along the upper beam (3;3';3'''' from a distal position (19b) toward the proximal end (3a) to the proximal position (19a), and from the proximal position (19a) to the distal position (19b), Lower beam (5; 5'; 5''') and A second linear actuator (21) is positioned along the lower beam (5; 5'; 5'''), and comprises a second carrier unit (21b; 21b'; 21b''') configured to travel along the lower beam (5; 5'; 5''') between a first position (23a) and a second position (23b), The main arm (7; 7') is pivotably connected to the proximal end (3a) of the upper beam (3; 3'; 3''') and the second carrier unit (21b; 21b'; 21b'''), An upper arm (9; 9') is pivotably connected to the main arm (7; 7') and the first carrier unit (21b; 21b'; 21b'''), A mounting structure (13;13′) is fixedly positioned with respect to the lower beam (5;5′), The lower arm (11; 11') is pivotably connected to the main arm (7; 7') and the mounting structure (13; 13'), It is equipped with Lift-tilt device (1;1').

2. When the first carrier unit (15b; 15b'; 15b'') is in the distal position (19b) and the second carrier unit (21b; 21b'; 21b'') is in the first position (23a), the lift-tilt device (1; 1') is in the folded state. The lift-tilt device (1;1') according to claim 1.

3. In the folded state, the upper beam (3; 3'; 3''') is arranged parallel to the lower beam (5; 5'; 5'''). The lift-tilt device (1;1') according to claim 2.

4. When the first carrier unit (15b; 15b'; 15b'') is located closer to the proximal position (19a) than the folded state, and the second carrier unit (21b; 21b'; 21b'') is located closer to the second position (23b) than the folded state, the lift-tilt device (1; 1') is in the lifted state. The lift-tilt device (1;1') according to claim 2 or 3.

5. In the lifted state, the upper beam (3; 3'; 3''') is parallel to the lower beam (5; 5'; 5'''). The lift-tilt device (1;1') according to claim 4.

6. The mounting structure (13; 13') is connected to the second end (5b) of the lower beam (5; 5'; 5'''), The second carrier unit (21b; 21b'; 21b''') is configured to reach the second position (23b) by traveling along the lower beam (5; 5'; 5''') from the first position (23a) toward the second end (5b). A lift-tilt device (1;1') according to any one of claims 2 to 5.

7. When the first carrier unit (15b; 15b'; 15b''') is in the distal position (19b) and the second carrier unit (21b; 21b'; 21b'''') is in the second position (23b), the lift-tilt device (1; 1') is in a tilted state. A lift-tilt device (1;1') according to any one of claims 1 to 6.

8. The aforementioned lift-tilt device (1;1') further, A first electric motor (17) configured to drive the first linear actuator (15a), A second electric motor (25) configured to drive the second linear actuator (21a), It is equipped with A lift-tilt device (1;1') according to any one of claims 1 to 7.

9. The lower beam (5; 5'; 5''') is configured to be fixedly attached to the chassis (41) of the electric wheelchair (39). A lift-tilt device (1;1') according to any one of claims 1 to 8.

10. The upper beam (3;3′;3′′′) and the lower beam (5;5′;5′′′) are included in the midline plane of the lift-tilt device (1;1′). A lift-tilt device (1;1') according to any one of claims 1 to 9.

11. In cross-section, each of the first and second carrier units (1b', 21b') is provided with a plurality of protrusions (35a to 35b) along its outer circumference. Each of the upper beam and the lower beam (3', 5') is, A plurality of flat support surfaces (32) configured to support one of the protruding portions (35a to 35b) of the first and second carrier units (1b', 21b'), Multiple sliding bearings (37) and It has, Each of the sliding bearings (37) is positioned between each of the protrusions (35a to 35b) and the support surface (32) to facilitate the axial movement of the first and second support units (15b', 21b') relative to each of the beams (3', 5'). A lift-tilt device (1') according to any one of claims 1 to 10.

12. For each of the first and second carrier units (1b', 21b'), the protrusions (35a to 35b) are two upper lateral protrusions (35a) and two lower lateral protrusions (35b), Each of the upper beam and the lower beam (3', 5') has four flat support surfaces (32) configured to support one of each of the lateral projections (35a, 35b). The lift-tilt device (1') according to claim 11.

13. Each of the support surfaces (32) forms a part of the respective grooves (30) in the upper beam and the lower beam (3', 5'), Each of the aforementioned lateral projections (35a, 35) is configured to travel within the groove (30). The lift-tilt device (1') according to claim 12.

14. Each of the first and second carrier units (15b′′′, 21b′′′) comprises a carrier unit body (47) and two lateral wing members (46), Each of the aforementioned lateral wing members (46) is attached to the respective side of the carrier unit body (47). A lift-tilt device according to any one of claims 1 to 10.

15. Each of the aforementioned lateral wing members (46) is provided with an upper projection (51a) and a lower projection (51b), The contoured inner surfaces of the upper beam (3′′′) and the lower beam (5′′′) are provided with a plurality of shoulder portions (53). Each of the shoulder portions (53) is positioned to guide one of the upper protrusions (51a) and the lower protrusions (51b), The lift-tilt device according to claim 14.

16. The lift-tilt device further includes a plurality of sliding bearings (37′′′), Each of the aforementioned sliding bearings (37′′′) is provided between each of the aforementioned shoulders (53) and one of the aforementioned upper protrusions (51a) or the aforementioned lower protrusions (51b). The lift-tilt device according to claim 15.

17. The upper beam (3'; 3''') has at least one open slot (34) to enable a pivot connection between the first carrier unit (15b'; 15b'') and the upper arm (9'), The lower beam (5'; 5''') has at least one open slot (34) to enable a pivot connection between the second carrier unit (21'b; 21b'') and the main arm (7'). A lift-tilt device (1') according to any one of claims 1 to 16.

18. The upper beam (3′; 3′′′) is provided with at least one flexible curtain (31) positioned to cover each of the at least one of the open slots (34) of the upper beam (3′; 3′′′), The lower beam (5'; 5''') comprises at least one flexible curtain (31) positioned to cover each of at least one of the open slots (34) of the lower beam (5'; 5'''). The lift-tilt device (1') according to claim 14.

19. Each of the aforementioned flexible curtains (31) is made of silicone. A lift-tilt device (1') according to claim 15. (20 The first linear actuator (15) is a first screw-type actuator equipped with a first rotatable screw (15a), The first carrier unit (15b; 15b'; 15b''') is configured to travel along the upper beam (3; 3'; 3'''), The second linear actuator (21) is a second screw-type actuator equipped with a second rotatable screw (21b), The second carrier unit (21b; 21b'; 21b''') is configured to travel along the lower beam (5; 5'; 5'''), A lift-tilt device (1;1') according to any one of claims 1 to 19).

20. The first linear actuator (15) is positioned inside the upper beam (3;3′;3′′′), The second linear actuator (21) is located inside the lower beam (5; 5'; 5'''), A lift-tilt device (1;1') according to any one of claims 1 to 19.

21. Each of the upper beams (3; 3'; 3''') and the lower beams (5; 5'; 5''') has one of the following structures: that is, it is formed integrally and has a rectangular cross-sectional shape, or it is formed from two U-shaped beams facing each other, or it is formed from one U-shaped beam. A lift-tilt device (1;1') according to any one of claims 1 to 20.

22. The device comprises a lift-tilt device (1;1') according to any one of claims 1 to 21. Electric wheelchair (39).

23. The electric wheelchair (39) further comprises a wheelchair chassis (41), The mounting structure (13; 13') is integrated with the wheelchair chassis (41) or attached to the wheelchair chassis (41). The lower beam (5; 5'; 5''') is either integrated with the wheelchair chassis (41) or attached to the upper part of the wheelchair chassis (41). The electric wheelchair (39) according to claim 22.

24. A lift-tilt device (45) for operating the seat (43) of an electric wheelchair (39), wherein the lift-tilt device (45) is Lower beam (5′′) and A linear actuator is arranged along the lower beam (5′′) and comprises a carrier unit configured to travel along the lower beam (5′′) between a first position and a second position, The main arm (7′′) is pivotably connected to the carrier unit, A mounting structure fixedly positioned with respect to the lower beam (5′′), The main arm (7′′) and the lower arm (11′′) are pivotably connected to the mounting structure, A lift-tilt device (45) is provided.

25. The lift-tilt device (45) further includes an electric motor (25) configured to drive the linear actuator. The lift-tilt device (45) according to claim 24.

26. The lower beam (5′′) is configured to be fixedly attached to the chassis (41) of the electric wheelchair (39). The lift-tilt device (45) according to claim 24 or 25.

27. The lower beam (5′′) is included in the midline plane of the lift-tilt device (45), A lift-tilt device (45) according to any one of claims 24 to 26.

28. In cross-section, the carrier unit (21b') is provided with a plurality of protrusions (35a to 35b) along its outer circumference. The aforementioned lower beam (5′′) is A plurality of flat support surfaces (32) are configured to support one of each of the protruding portions (35a to 35b) of the carrier unit (21b'), Multiple sliding bearings (37) and It has, Each of the sliding bearings (37) is positioned between each of the protrusions (35a to 35b) and the support surface (32) to facilitate the axial movement of the carrier unit (21b') relative to the lower beam (5''). A lift-tilt device (45) according to any one of claims 24 to 27.

29. The multiple protrusions (35a to 35b) consist of two upper lateral protrusions (35a) and two lower lateral protrusions (35b), The lower beam (5′′) has four flat support surfaces (32) configured to support one of each of these lateral protrusions (35a, 35b). The lift-tilt device (45) according to claim 28.

30. Each of the support surfaces (32) forms a part of each groove (30) within the lower beam (5′′), Each of the aforementioned lateral protrusions (35a, 35b) is configured to travel inside each of the aforementioned grooves (30). The lift-tilt device (45) according to claim 29.

31. The carrier unit (21b'') comprises a carrier unit body (47) and two lateral wing members (46). Each of the aforementioned lateral wing members (46) is attached to the respective side of the carrier unit body (47). A lift-tilt device (45) according to any one of claims 24 to 27.

32. Each of the aforementioned lateral wing members (46) is provided with an upper projection (51a) and a lower projection (51b), The contoured inner surface of the lower beam (5′′′) is provided with a plurality of shoulder portions (53), Each of the shoulder portions (53) is positioned to guide one of the upper protrusions (51a) and the lower protrusions (51b), The lift-tilt device (45) according to claim 31.

33. The lift-tilt device (45) is further equipped with a plurality of sliding bearings (37′′′), Each of the aforementioned sliding bearings (37′′′) is provided between each of the aforementioned shoulders (53) and one of the aforementioned upper protrusions (51a) or the aforementioned lower protrusions (51b), The lift-tilt device (45) according to claim 32.

34. The lower beam (5′′) has at least one open slot (34) to enable a pivot connection between the carrier unit (21′b) and the main arm (7′′). A lift-tilt device (45) according to any one of claims 24 to 33.

35. The lower beam (5′′) comprises at least one flexible curtain (31) positioned to cover each of at least one of the open slots (34) of the lower beam (5′). The lift-tilt device (45) according to claim 34.

36. Each of the aforementioned flexible curtains (31) is made of silicone. The lift-tilt device (45) according to claim 35.

37. The linear actuator is a screw-type actuator equipped with a rotatable screw, The carrier unit is configured to travel along the lower beam (5′′). A lift-tilt device (45) according to any one of claims 24 to 36.

38. The linear actuator is positioned inside the lower beam (5′′). A lift-tilt device (45) according to any one of claims 24 to 37.

39. The lower beam has one of the following structures: that is, it is formed integrally and has a rectangular cross-sectional shape, or it is formed from two U-shaped beams facing each other, or it is formed from one U-shaped beam. A lift-tilt device (45) according to any one of claims 24 to 38.

40. The device comprises a lift-tilt device (45) according to any one of claims 24 to 39. Electric wheelchair (39).

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