WO2025115046A1

WO2025115046A1 - Floating wheelchair

Info

Publication number: WO2025115046A1
Application number: PCT/IT2024/050237
Authority: WO
Inventors: Antonio SAVOLDI
Original assignee: Salong Srl
Current assignee: Salong Srl
Priority date: 2023-11-27
Filing date: 2024-11-19
Publication date: 2025-06-05
Anticipated expiration: 2026-05-27
Also published as: IT202300025206A1

Abstract

Floating wheelchair (1 ) comprising: - a frame (2), - two floating rear wheels (6) mounted on the frame (2), and - a front wheel (7) mounted on the frame (2), and - a movement system (8) for moving the rear wheels (6) alternatively between a terrestrial position, in which the rear wheels are facing each other on opposite sides of the frame with substantially transversal rotation axis (9), and an aquatic position in which the rotation axis (9) of the rear wheels is substantially vertical.

Description

DESCRIPTION

Title: FLOATING WHEELCHAIR

Technical field of the invention

The present invention relates to a floating wheelchair capable of facilitating people with reduced mobility (e.g. disabled, elderly, patients, etc.) in swimming.

Prior art

Amphibious wheelchairs are known, that is, capable of both moving on the ground and facilitating people with reduced mobility in swimming.

For example EP2777961A1 describes an amphibious wheeled vehicle selectively configurable in a terrestrial configuration, in which the main wheels roll on the ground, and an aquatic configuration, in which the main wheels are lifted and mutually distanced and in which the vehicle floats in the water.

Summary of the invention

By "substantially parallel/orthogonal", in relation to a spatial relationship between two geometric elements (lines, planes, etc.) is meant that these elements mutually form an angle of 0°+/-20°, preferably 0°+/-15°, or, respectively, 90°+/-20°, preferably 90°+/-15°.

By "substantially horizontal/vertical" in relation to an element of the machine is meant that this element (or a geometric element representative of the element) forms with the horizontal/vertical direction an angle of 0°+/-20°, preferably 0°+/-15°.

The terms "horizontal", "vertical", "upper", "lower", "top", "high", "low" and the like refer to the geographical vertical direction under normal conditions of use of the wheelchair.

The terms "front" and "rear" refer to the oriented direction of advancement of the wheelchair.

By "direction of advancement" is meant the oriented horizontal direction of normal advancement of the wheelchair and by "transverse direction" is meant the horizontal direction orthogonal to the direction of advancement.

By "rotation axis" of a wheel is meant the normal axis around which the wheel can turn in normal use in which the wheel rolls on the ground.

The Applicant has realised that the known amphibious wheelchairs have some disadvantages or can be improved in some respects.

The Applicant has addressed the problem of making a floating wheelchair with high floating properties and/or high floating stability, and at the same time structurally simple and light and/or easy to use.

According to the Applicant one or more of the above problems are solved by a wheelchair in accordance with the appended claims and/or having one or more of the following features.

According to one aspect the invention relates to a floating wheelchair comprising:

- a frame,

- two floating rear wheels mounted on the frame, and

- at least one front wheel mounted on the frame.

Preferably, the wheelchair comprises a movement system for moving the rear wheels alternatively between a terrestrial position, in which the rear wheels are facing each other on opposite sides of the frame with substantially transversal rotation axis, and an aquatic position in which said rotation axis of the rear wheels is substantially vertical.

The Applicant has realised that the movement of the rear wheels in the aforementioned aquatic position causes the hydrostatic thrust received by the rear wheels to be applied at the user's body, thus favouring the floating and/or balancing in water of the wheelchair, and reducing the risk of overturning the wheelchair forwards and/or backwards. In the opposite case where, as for example in EP2777961A1 , the front wheels are moved to change configuration, the wheelchair is unbalanced towards the rear side, with a consequent risk of overturning (a risk that in EP2777961 A1 requires the use of additional floats).

The present invention may have one or more of the following preferred features. Preferably said frame comprises a seat support.

Preferably said rotation axis of the rear wheels in the terrestrial position is in rear position, more preferably vertically beneath, or rearward of, said seat support.

Preferably in the aquatic position the rear wheels are completely above said seat support (to favour the user diving in water).

Preferably said front wheel is floating. In this way, flotation in the aquatic position is facilitated and balanced.

Preferably said wheelchair comprises a respective rod, more preferably tubular, which respectively connects each of said rear wheels and said front wheel to said frame. Each wheel is rotatably mounted to a lower end of the respective rod. Preferably each respective rod of the rear wheels is arranged with a vertical component, more preferably substantially vertically, in the terrestrial position (more preferably it extends parallel to the backrest support), and substantially horizontally in the aquatic position of the respective wheel.

Preferably said respective rod of the front wheel is rigidly connected to said frame. In this way, the front wheel ensures contact with the shallow seabed, for example when putting the wheelchair into the water or while swimming.

Preferably said frame consists of respective tubular rods. In this way, the wheelchair is structurally simple and lightweight, also favouring floatation.

Preferably said rods are made of steel, aluminium, carbon or titanium, more preferably they are made of aluminium (to make the wheelchair light).

Preferably said frame comprises a backrest support, more preferably rearward hinged to the rest of said frame (e.g. to the seat support) at a lower end of said backrest support for tilting around a substantially transverse hinge axis. Preferably said movement system is structured to move said backrest support, preferably simultaneously with the movement of the rear wheels between the terrestrial and the aquatic position, between a raised position, preferably when the rear wheels are in the terrestrial position, and a reclined position, preferably when the rear wheels are in the aquatic position, in which the backrest support is rotated more towards the horizontal plane compared to the raised position. This favours the full diving of the user.

Preferably each rod of said rear wheels is hinged to said frame, more preferably to said backrest support, via a first hinge arranged in an upper portion of the rod. Preferably said first hinge has a first hinge axis having a component along the direction of advancement, more preferably orthogonal to the transversal direction (e.g. substantially parallel to the direction of advancement in the terrestrial position), even more preferably said first hinge axis is always kept orthogonal to a main lying plane of the backrest support.

Preferably said first hinge is at a height greater than a height of said seat support (in this way the radius of rotation of the rear wheels around the first hinge axis is increased, achieving a wide distance between the rotation axes of the wheels in the aquatic position to the advantage of floating stability).

Preferably, the movement system comprises, for each rod of the rear wheels, an arm (e.g. rigid) connected, at an upper end thereof, to the rod via a second hinge arranged above the first hinge, the second hinge more preferably having a second hinge axis parallel to the first hinge axis. Preferably in the transition from the terrestrial position to the aquatic position of each rear wheel, the respective arm moves downward the respective second hinge, rotating the respective rod around the first hinge axis and lifting the respective rear wheel (in other words the rod acts as a first-class lever where the wheel is the resistance, the first hinge axis is the fulcrum and the arm/second hinge is the force). Preferably, the movement system comprises an electric battery and an electric actuator for moving said arms and/or said backrest support. Preferably said electric actuator comprises a linear actuator, e.g. telescopic, having an upper end movable and connected to both said arms, and more preferably to said backrest support, and a lower end fixed and connected to said frame.

Preferably the movement system comprises a guide mounted on the frame, more preferably on said backrest support, and a slider which slidingly engages the guide, wherein said upper end of the linear actuator and lower ends of both arms are hinged on said slider. In this way, the simultaneous movement of the wheels and the backrest is obtained in a simple and effective way.

Preferably the wheelchair comprises, for each rear wheel, a locking/unlocking device structured to lock the rear wheel in the terrestrial position, in which the rear wheel can rotate only around the respective rotation axis, and to allow the rear wheel, in the aquatic position, to tilt around a tilting axis orthogonal to the respective rotation axis, more preferably (substantially) transverse. In this way the wheels can be arranged horizontally and, if necessary, tilted passively following the waves of the water, reducing the pitch of the wheelchair in the water.

Preferably the wheelchair comprises at the front two footrest elements and two respective rods, more preferably tubular, which respectively connect each footrest element to said frame, wherein each rod of the footrest elements is hinged to said frame at an upper end of the rod for tilting upwards about a respective substantially transverse hinge axis. Preferably said footrest elements are floating. In this way, in the water, the footrest elements are lifted by hydrostatic thrust, giving the user a semi-lying position for a better diving experience.

In one embodiment said rear wheels and/or said front wheel and/or said footrest elements are made of plastic material, such as for example polyvinylchloride (PVC) or polyethylene (PE), hollow or filled with low density material such as for example polyurethane (Pll) or expanded polystyrene (PS). Preferably the rear wheels are covered by a tread band in elastomeric compound.

Preferably said wheelchair is floating also with a user sitting on the wheelchair (e.g. up to 100kg or 120kg of user's weight).

Brief description of the figures

Figures 1 -3 show schematically and partially some views from different angles of a wheelchair according to the present invention in a terrestrial configuration; figures 4-6 show schematically and partially some views from different angles of the wheelchair of figures 1 -3 in aquatic configuration.

Detailed description of some embodiments of the invention

The features and advantages of the present invention will be further clarified by the following detailed description of some embodiments, presented by way of example and not by way of limitation of the present invention, with reference to the appended figures. A floating wheelchair according to the present invention is indicated in the figures with number 1 .

The wheelchair has associated a direction of advancement 100 oriented in the rear-front direction as shown by the arrow in figures 1 and 3, and a horizontal transverse direction 101 (shown exemplarily in figure 1 passing through the rotation axes of the rear wheels and in figure 2 passing through the hinge axis 5). The vertical direction 102 is also shown. The wheelchair comprises a frame 2 substantially consisting of tubular (i.e. hollow) rods made of aluminium.

Preferably, the frame comprises a seat support 3 (fixed) and a backrest support 4 (having an inverted "U" shape), the latter hinged, at a lower end thereof, to a rear end of the seat support, in order to be able to tilt around a transverse hinge axis 5. In use, the seat support and/or backrest support may be upholstered and/or padded, possibly with floating material.

The wheelchair comprises, mounted on the frame, two floating rear wheels 6 and a front wheel 7 (shown in figures 1 and 4 and removed in the remaining figures for better clarity). Preferably the wheelchair comprises a movement system 8 for moving the rear wheels alternatively between a terrestrial position (fig 1 -3), in which the rear wheels are facing each other on opposite sides of the frame with transversal rotation axis 9, and an aquatic position (fig 4-6) in which the rotation axis 9 of the rear wheels 6 is substantially vertical. Preferably, the rotation axis 9 of the rear wheels in the terrestrial position is in rear position and vertically beneath the seat support (fig. 3).

Preferably in the aquatic position the rear wheels 6 are located completely above the seat support (fig 4).

Preferably the wheelchair 1 comprises a respective tubular rod 10 which respectively connects each rear wheel 6 and the front wheel 7 to the frame, wherein each wheel is rotatably mounted to a lower end of the respective rod. Preferably each rod 10 of the rear wheels, in the terrestrial position, extends parallel to the backrest support, while in the aquatic position it extends horizontally. Preferably the rod 10 of the front wheel 7 is rigidly connected to the frame 3.

Preferably each rod 10 of the rear wheels 6 is hinged to the backrest support 4 via a first hinge 11 arranged in an upper portion of the rod 10 and having a first hinge axis 12 orthogonal to the transverse direction and orthogonal to a main lying plane of the backrest support 4. Preferably, the first hinge 11 is at a height greater than a height of the seat.

Preferably, the movement system 8 comprises, for each rod 10 of the rear wheels, an arm 13 having an upper end connected to the rod 10 via a second hinge 14 arranged above the first hinge 11 , the second hinge having a second hinge axis parallel to the first hinge axis 12.

Preferably, the movement system 8 comprises an electric battery 15 and an electric actuator 16 for moving both the arms 13 and the backrest support 4.

In an alternative embodiment, not shown, the movement system is manual and purely mechanical.

Preferably the electric actuator comprises a telescopic linear actuator 17, having a lower end fixed and connected to the frame and an upper end movable and hinged to a slider that slidingly engages a guide mounted on the backrest support 4. connected to both said tie rods, and more preferably to said backrest support. The lower ends of both arms are also hinged to the slider.

In this way, in the transition from the terrestrial position to the aquatic position, the upper end of the linear actuator 17 descends downwards by sliding the slider down along the guide, to thus move the backrest support 4 from a raised position (fig. 3), in the terrestrial configuration of the wheelchair, to a reclined position (fig. 6), in the aquatic configuration, in which the backrest support is rotated more towards the horizontal plane than to the raised position. At the same time, the linear actuator 17 also drags downwards the lower ends of the arms 13, the upper ends of which rotate the respective rod 10 about the first hinge axis 12, thus lifting the respective rear wheel 6. In the transition from the aquatic to the terrestrial position, the movement of the various members occurs in reverse.

Preferably, the wheelchair 1 further comprises, for each rear wheel 6, a locking/unlocking device 40 comprising a rotatable coupling 42 that couples the wheel hub 44 to the frame 2 (e.g. to the respective rod 10) in a rotatable manner around a tilting axis 43, and a seat 41 , rigidly connected to said frame, which in the terrestrial position houses the hub 44 of the rear wheel and shaped to lock the tilting of the hub 44 around the tilting axis 43.

Preferably, the wheelchair 1 comprises at the front two floating footrest elements 30 and two respective tubular rods 31 which respectively connect each footrest element to the frame (e.g. to the seat support), wherein each rod of the footrest elements is hinged to the frame at an upper end of the rod for tilting upward around a respective transverse hinge axis.

Exemplarily, the rear wheels and/or the footrest elements are made of PVC. In an alternative embodiment, the rear wheels are pneumatic or at least with an elastomeric compound tread, so as to facilitate movement on the ground, even hard, in the terrestrial configuration.

In use, in the terrestrial configuration the wheelchair is used as a normal wheelchair, with the possibility of advancement even on a yielding ground such as sand or gravel thanks to the size and shape of the wheels. The wheel hubs 44 are locked within the seats 41 . To allow a water diving experience for the user, the wheelchair is advanced into the body of water (e.g. sea, lake or pool) by rolling all three wheels on the seabed as far as the height of the seabed allows it. During this approach, the wheelchair is pushed in reverse (i.e. in the opposite direction to the normal direction of advancement) or in any case rotates in the front-rear direction, so that the front wheel is facing the most shallow seabed and therefore remains resting on the seabed for longer, while the rear wheels are facing the deepest seabed, so as to allow their lifting, or almost, as first from the sea floor. At this point, the movement system 8 is operated to lift the rear wheels and simultaneously recline the backrest. As soon as the wheel hubs 44 leave the seats 41 , they are free to tilt around the tilting axis 43. As the wheelchair progressively enters the water, the footrest elements 30 are progressively lifted by hydrostatic thrust.

Once the aquatic configuration is reached, the rear wheels 6 float on the water surface, unlocked so as to be able to tilt around the tilting axis 43 (arranged parallel to the transverse direction 20), to follow the waves around a horizontal position (e.g. perfectly calm water) in which the rotation axis 9 of the rear wheels is horizontal. The front wheel 7, fixed, can remain resting on the seabed, giving stability to the wheelchair, or detach from it, in the event of total floatation of the wheelchair. The user is thus in a semi-lying position almost completely immersed in the water.

Claims

1. Floating wheelchair (1 ) comprising:

- a frame (2),

- two floating rear wheels (6) mounted on the frame (2),

- at least one front wheel (7) mounted on the frame (2), and

- a movement system (8) for moving the rear wheels (6) alternatively between a terrestrial position, in which the rear wheels are facing each other on opposite sides of the frame with a substantially transversal rotation axis (9), and an aquatic position in which said rotation axis (9) of the rear wheels is substantially vertical.

2. Wheelchair (1 ) according to claim 1 , wherein the frame comprises a seat support (3), where the rotation axis (9) of the rear wheels (6) in the terrestrial position is in rear position and vertically beneath, or rearward of, said seat support (3) and wherein in the aquatic position the rear wheels (6) are completely above said seat support (3).

3. Wheelchair (1 ) according to any one of the preceding claims, comprising a respective rod (10), tubular, which respectively connects each of said rear wheels and said front wheel to said frame, wherein each respective rod of the rear wheels (6) is arranged with a vertical component in the terrestrial position of the respective wheel, and substantially horizontally in the aquatic position of the respective wheel, and wherein said respective rod (10) of the front wheel (7) is rigidly connected to said frame.

4. Wheelchair (1 ) according to any of the previous claims, wherein said frame is made up of respective tubular aluminium rods, wherein said frame includes a backrest support (4) rearward hinged to the rest of said frame at a lower end of said backrest support for tilting around a substantially transversal hinge axis (5), and wherein said movement system (8) is structured to move said backrest support, simultaneously with the movement of the rear wheels between the terrestrial and aquatic position, between a raised position, when the rear wheels are in the terrestrial position, and a reclined position, when the rear wheels are in the aquatic position, in which the backrest support is rotated more towards the horizontal plane compared to the raised position.

5. Wheelchair (1 ) according to any one of claims 3 and 4, where each rod (10) of said rear wheels (6) is hinged to said frame via a first hinge (11 ) arranged in an upper portion of the rod at a height greater than a height of said seat support, and having a first hinge axis (12) having a component along the direction of advancement, wherein the movement system (8) comprises, for each rod (10) of the rear wheels, a rigid arm connected, at an upper end thereof, to the rod via a second hinge (14) arranged above the first hinge (11 ), and wherein in the passage from the terrestrial position to the aquatic position of each rear wheel, the respective arm moves downward the respective second hinge, rotating the respective rod around the first hinge axis and lifting the respective rear wheel.

6. Wheelchair (1 ) according to any of the previous claims, wherein the movement system (8) comprises an electric battery (15) and an electric actuator (16) for moving said arms (13) and said backrest support (4), said electric actuator comprising a linear actuator (17) having a movable upper end connected to both said arms (13) and said backrest support, and a fixed lower end connected to said frame.

7. Wheelchair (1 ) according to claim 6, wherein the movement system (8) comprises a guide mounted on said backrest support, and a slider which slidingly engages the guide, wherein said upper end of the linear actuator (17) and lower ends of both arms (13) are hinged on said slider.

8. Wheelchair (1 ) according to any one of the preceding claims, further comprising, for each rear wheel (6), a locking/unlocking device (40) structured to lock the rear wheel in the terrestrial position, in which the rear wheel can rotate only around the respective rotation axis (9), and to allow the rear wheel (6), in the aquatic position, to tilt around a tilting axis (43) orthogonal to the respective rotation axis.

9. Wheelchair (1 ) according to any one of the previous claims, further comprising frontward two floating footrest elements (30) and two respective rods (31 ) which respectively connect each footrest element to said frame, wherein each rod of the footrest elements is hinged to said frame at an upper end of the rod for tilting upwards around a respective substantially transverse hinge axis.

10. Wheelchair (1 ) according to any one of the previous claims, wherein said rear wheels and/or said footrest elements are made of plastic material, said plastic material being polyvinyl chloride (PVC) or polyethylene (PE), hollow or filled with low density material.