Patent Description:
More specifically, the invention proposes the development of an auxiliary mobility system for a wheelchair which, due to its particular design, enables the reversible conversion of a wheelchair of the conventionally known type into a chair in the manner of a tricycle in a simple and practical manner.

Wheelchairs used for use by disabled persons are known in the current state of the art.

The wheelchairs known and used to date have effective operation and adaptation in places with small and eminently flat dimensions, and for travelling short distances. However, in the case of longer distances and particularly of more irregular floors, their features are more limited.

A possible solution for this reduction in features is the conversion of the chair with two wheels into a chair with three wheels in the manner of a tricycle, with an additional central and front wheel, which is also used as a governor to control the direction of movement of the chair.

This new chair design offers enhanced features in its operation, both in terms of stability particularly on irregular floors and in terms of its capacity to be driven and controlled by the user.

The solutions known to date in the state of the art to perform said conversion involve the inclusion of a sleeve mechanism and do not allow correct adaptation of the resulting geometry of the chair to the different ergonomic needs of different users; in addition, its installation and fit is highly complex and cumbersome for the user, and also requires the intervention of an installer for such purpose.

The regulation of some of the characteristic parameters in the resulting geometry involves the unwanted alteration of others, even preventing final coupling to the wheelchair.

The present invention contributes to solving this problem, as it enables the conversion of a traditional wheelchair into a chair in the manner of a tricycle, with the advantages inherent to its features, in a simple and practical way for the user.

Document <CIT> discloses a mounting assembly for attaching auxiliary equipment to a wheelchair including adjustment features.

Document <CIT> discloses an assembly and positioning mechanism for wheelchair and auxiliary operating lever. The assembly and positioning mechanism has a swinging angular adjustment seat and a liftable pivoting seat of operating lever.

Document <CIT> discloses a removable motor power device for wheelchair.

The present invention has been developed for the purpose of providing an auxiliary mobility system for a wheelchair, which comprises a frame, at least one wheel-bearing part and at least one steering element or handlebar, wherein the bearing part is associated with the frame such that it rotates concentrically about its own axial axis under the action of the steering element and is characterised essentially in that it comprises means for rotating the bearing part concentrically in relation to an axis substantially parallel to the rotation axis of the wheel.

Preferably, the auxiliary mobility system for a wheelchair comprises horizontal means for regulating the horizontal distance of the frame in relation to the chair in the longitudinal direction of movement of the chair itself.

Additionally, the auxiliary mobility system for a wheelchair comprises vertical means for regulating the vertical distance of the frame in relation to the rolling floor of the chair.

Furthermore, in the auxiliary mobility system for a wheelchair, the horizontal regulation means are embodied by a telescopic system, wherein one end thereof is associated with the frame and the other end is associated with the chair.

Alternatively, in the auxiliary mobility system for a wheelchair, the vertical regulation means are embodied by an implement movable by guides made in the frame and having tightening means for fixing the implement in its travel along the guides.

In addition, in the auxiliary mobility system for a wheelchair, the tightening means are embodied by screwing elements.

Likewise, in the auxiliary mobility system for a wheelchair, the rotation means of the bearing part are embodied by at least one recess in the manner of a hole positioned on the frame, and at least one protrusion associated with the bearing part and adapted to fit into said recess, such that the bearing part can pivot in relation to the frame itself.

Preferably, in the auxiliary mobility system for a wheelchair, the steering element or handlebar is movable in the axial direction of the bearing part.

Additionally, in the auxiliary mobility system for a wheelchair, the bearing part comprises a fork.

Furthermore, in the auxiliary mobility system for a wheelchair, the concentric axis of the rotation means and the rotation axis of the wheel are coincident.

Alternatively, the auxiliary mobility system for a wheelchair includes driving means.

In addition, in the auxiliary mobility system for a wheelchair, the driving means are embodied by a rack-and-pinion system which is manually actuated and exerts a traction force on the wheel.

Likewise, in the auxiliary mobility system for a wheelchair, the driving means are embodied by a motor associated with the wheel.

In the same manner, the auxiliary mobility system for a wheelchair comprises a battery system enabled for supplying power to the motor.

Likewise, the auxiliary mobility system for a wheelchair comprises wheel braking means.

Thanks to the present invention, the simple, practical and effective conversion of a traditional wheelchair into a tricycle is achieved, with the associated added advantages and features.

In addition, the user does not require the presence of an installer for such purpose, to carry out the regulation of the different characteristic parameters in the resulting geometry.

Other characteristics and advantages of the auxiliary mobility system for a wheelchair will be evident in the description of a preferred but not-limiting embodiment, illustrated by way of non-limiting example in the accompanying drawings, wherein:.

<FIG> shows a schematic representation of a preferred embodiment of the auxiliary mobility system for a wheelchair of the invention.

As shown in <FIG>, the auxiliary mobility system for a wheelchair, which comprises a frame (<NUM>), one wheel-bearing part (<NUM>) and one steering element (<NUM>) or handlebar, said bearing part being associated with the frame (<NUM>) such that it can rotate concentrically about its own axial axis under the action of the steering element (<NUM>) comprises means for rotating the bearing part concentrically in relation to an axis substantially parallel to the rotation axis of the wheel (<NUM>).

In this preferred embodiment schematically represented in <FIG>, the frame (<NUM>) has two parallel plates (<NUM>), between which a sleeve (<NUM>) is positioned and secured.

The bearing part is embodied by a fork (<NUM>), which is housed in turn inside the sleeve (<NUM>) and concentrically therewith. The fork (<NUM>) rotates inside the sleeve (<NUM>), concentrically about its axial axis.

The fork (<NUM>) bears a front wheel (<NUM>) at its forked end. At its other opposite end it has in turn a steering element (<NUM>) or handlebar, wherewith it can be rotated and therefore rotate the wheel (<NUM>), in a manner similar to a bicycle or motorcycle.

The frame (<NUM>) comprises rotation means which enable the sleeve (<NUM>) inserted between the plates (<NUM>) of the frame (<NUM>) to pivot concentrically in relation to an axis substantially parallel to the rotation axis of the wheel (<NUM>).

In this preferred embodiment, the rotation means are embodied by openings (<NUM>) in the manner of holes positioned on the plates (<NUM>) parallel and adjacent to the sleeve (<NUM>), which is positioned between said plates (<NUM>), and protrusions (<NUM>) in the sleeve (<NUM>), adapted to fit in such openings (<NUM>), in the manner of a tongue-and-groove joint.

For a person skilled in the art, other possible embodiments will be possible such as, for example, that the openings (<NUM>) are associated with the sleeve (<NUM>) and the protrusions (<NUM>) are on the plates (<NUM>).

According to the fit of the protrusions (<NUM>) of the sleeve (<NUM>) in the openings (<NUM>) of the plates (<NUM>), the sleeve (<NUM>) and therefore the fork (<NUM>) will have a different degree of rotation within their insertion between the plates (<NUM>) of the frame (<NUM>).

In this preferred embodiment, the concentric axis of the rotation means and the rotation axis of the wheel (<NUM>) are coincident.

The frame (<NUM>) also comprises vertical regulation means. Vertical is understood to be a direction substantially perpendicular to the rolling floor of the chair. Such vertical regulation means enable the regulation of the vertical distance of the frame (<NUM>) in relation to the rolling floor of the chair.

In this embodiment, the vertical regulation means are embodied by guides (<NUM>) enabled in the two parallel plates (<NUM>) of the frame (<NUM>) and an implement (<NUM>) enabled for travelling along the guides (<NUM>), functioning in a manner similar to a slide system.

Such implement (<NUM>) is movable through the inside of the guides (<NUM>) and has tightening means in order to be fixed and immobilised in a certain position on the guides (<NUM>).

In this preferred embodiment, such tightening means are embodied by screwing elements which enable the fixation and immobilisation of the implement (<NUM>) in a certain position in its travel along the guides (<NUM>).

The frame (<NUM>) also comprises horizontal regulation means. Horizontal is understood to be a direction substantially parallel to the rolling floor of the chair. Such horizontal regulation means enable the regulation of the horizontal distance of the frame (<NUM>) in relation to the chair and in the longitudinal direction of the movement of the chair.

In this preferred embodiment, the horizontal regulation means are embodied by a telescopic system constituted by a telescopic rod (<NUM>) of variable and fixable length. Such telescopic rod (<NUM>) is in turn joined at one of its ends to the implement (<NUM>).

At the other end of the telescopic rod (<NUM>) it is associated with the chair. In this preferred embodiment, such connection is established by a manual and reversible coupling system (<NUM>) to the chair. Such manual coupling system is enabled for the manual and reversible fixation thereof to the chair and not is not an object of the present invention and does not appear represented in detail in <FIG>.

In its use, and in this preferred embodiment, the auxiliary mobility system for a wheelchair of the invention is coupled to the chair by means of the manual coupling system (<NUM>).

Immediately thereafter, through the regulation of the variable length of the telescopic rod (<NUM>), the extension in the horizontal axis of the positioning of the frame (<NUM>) in relation to the chair is regulated.

Next, through the travel and subsequent fixation of the implement (<NUM>) on the guides (<NUM>), the extension is regulated in the vertical axis of the positioning of the frame (<NUM>) in relation to the chair.

Next, through the fitting of the protrusions (<NUM>) of the sleeve (<NUM>) in the different openings (<NUM>) of the plates (<NUM>), the desired degree of inclination is conferred to the sleeve (<NUM>) and therefore to the fork (<NUM>) in relation to the horizontal or vertical axis.

The order of the described operations is not imperative and is selected by the user and/or installer.

The steering element (<NUM>) or handlebar can also be regulated in its movement in the axial direction of the sleeve (<NUM>), in a similar manner to that of a bicycle of those commonly known in the state of the art.

The auxiliary mobility system for a wheelchair of the invention may also include movement means that provide the resulting chair-tricycle with the possibility of aiding its movement.

The movement means may be embodied by a rack-and-pinion system manually actuated by the user that transmits traction to the wheel (<NUM>) or by a motor motively associated with the wheel (<NUM>).

In this preferred embodiment, the invention also comprises a battery system (<NUM>) enabled to supply power to the motor.

Additionally, it also comprises wheel (<NUM>) braking means embodied by a disc braking system (<NUM>).

All the different features described enable the adaptation and conversion of a wheelchair in the manner of a tricycle, with an added central and front wheel, which is also used as a governor of the direction of the movement of the chair and even as a traction element.

In addition, the proposed invention is very effective in the regulation and adaptation of the resulting geometry in the chair to the user's different ergonomic needs, all in a simple, practical and quick manner for the user, without requiring the intervention of an installer for such purpose.

Claim 1:
An auxiliary mobility system for a wheelchair, which comprises a frame (<NUM>), at least one wheel-bearing part and at least one steering element (<NUM>) or handlebar, said bearing part being associated with the frame (<NUM>) such that the wheel-bearing part can rotate concentrically about its own axial axis under the action of the steering element (<NUM>), the frame has two parallel plates (<NUM>), between which a sleeve (<NUM>) is positioned and secured;
wherein the bearing part comprises a fork (<NUM>); the fork is housed inside the sleeve (<NUM>) and concentrically therewith;
characterized in that the auxiliary mobility system comprises means for rotating the bearing part and the sleeve with respect to the frame concentrically, in relation to a horizontal axis perpendicular to the longitudinal direction of the movement of the chair and to the wheel (<NUM>); wherein the rotation means of the bearing part are embodied by openings (<NUM>) in the manner of holes on the plates (<NUM>) or the sleeve (<NUM>) and protrusions (<NUM>) in the sleeve connected to the bearing part or on the plates (<NUM>) and adapted to fit in said openings (<NUM>), such that the bearing part may pivot in relation to the frame (<NUM>) itself; and
wherein the system comprises means for vertically regulating the vertical distance of the frame (<NUM>) in relation to the rolling floor of the chair, the vertical regulation means being embodied by an implement (<NUM>) movable along guides (<NUM>) enabled in the two parallel plates (<NUM>) of the frame (<NUM>) and having tightening means for fixing the implement (<NUM>) in its travel along the guides (<NUM>).