Motorisation device for wheelchair

Abstract

A motorization device (1)a wheelchair (10) is provided; the wheelchair (10) comprises a frame (11); a posture system (12) constrained to the frame (11); and at least one wheel (131, 132) hinged to the frame and defining a tread (13a); the motorization device (1) comprises a rolling element (2) configured to contact the wheel (131, 132) at the tread (13a); a motor (3) kinematically connected to the rolling element (2) so as to rotate it by controlling the rotation of the wheel (131, 132) and thus the movement of the wheelchair (10); an sensor unit (4) configured to detect the tilt of the motorization device (1); and a control board (5) configured to control the motor (3) according to the sensor unit (4).

Description

[0001] This finding is for a motorisation device of the type specified in the preamble to the first claim.

[0002] In detail, the device is configured to be attached to a wheelchair enabling the wheelchair user to negotiate otherwise difficult routes (such as a climb) and / or defining a manual propulsion aid for those with upper limb mobility.

[0003] As is well known, a wheelchair (commonly called a "carrozzina") is a mobile device on wheels used by those who finds difficult or impossible to walk due to illness, injury, and disability.

[0004] The main parts of a wheelchair are frame, posture system and moving block.

[0005] The frame identifies the entire scaffolding of the wheelchair and holds all the other components together. It can be of various shapes, sizes, and weights. It can be rigid if made of a few pieces that hold each other together or collapsible if made of two separate sides joined together by the canvas part. This allows the wheelchair to be easily folded and loaded into the car.

[0006] The posture system comprises a seat, backrest, and foot support structure. Various accessories (such as armrests, side rails, side supports, headrest and table) configured both to enable the maintenance of a comfortable posture and to ensure greater usability of the wheelchair can be added to these components.

[0007] Finally, the moving block consists of the wheels (usually two larger rear wheels and two smaller front wheels), handrails (hoops constrained to the wheels in order to allow the user autonomous movement), and brakes. There can also be additional levers and wheels to prevent wheelies and tipping.

[0008] The known technique described comprises some important drawbacks.

[0009] In particular, the movements, being manually controlled by pushing the handrails, are often difficult and very tiring. This drawback is accentuated when facing uphill or rough paths where the effort required is greater and / or it is difficult to act on the handrails.

[0010] It is pointed out that, to solve this drawback, there are motorized wheelchairs equipped with electric motors integral to the frame and having output shaft committed to the rear wheels so as to control their motion.

[0011] These wheelchairs have major drawbacks. In fact, presenting the output shaft committed to the rear wheels, they force the use of motors for any movement imposing the adoption of batteries of considerable size and therefore encumbrance. This aspect also results in greater bulk and, above all, in an inability to fold the wheelchair and in a reduced transportability.

[0012] Another drawback of motorized wheelchairs is that the motor and batteries are particularly heavy. As a result, the wheelchairs are very weighty causing difficulties in transportation and high motor consumption (thus battery life).

[0013] In this situation, the technical task underlying the present finding is to develop a motorisation device that can substantially obviate at least part of the aforementioned drawbacks.

[0014] Within the scope of the said technical task, it is an important purpose of the invention to obtain a motorisation device that enables a wheelchair easily movable along any path even if it is rough and / or uphill.

[0015] Another important purpose of the invention is to make a motorisation device that can be easily applied even to originally non-motorized wheelchairs."

[0016] Another important purpose of the invention is to make an easy-to-transport motorisation device.

[0017] The specified technical task and purposes are achieved by a motorisation device as claimed in the attached claim 1. Examples of preferred implementation are described in the dependent claims.

[0018] The features and advantages of the invention are clarified below by the detailed description of preferred executions of the invention, with reference to the united drawings, in which: Fig. 1 shows, to scale, a wheelchair presenting a motorisation device according to the invention; Fig. 2 illustrates, to scale, a side view of the wheelchair in Fig. 1; and Fig. 3 presents, to scale, a section of a motorisation device detail according to the invention.

[0019] In this document, measurements, values, shapes, and geometric references (such as perpendicularity and parallelism), when associated with words such as "approximately" or other similar terms such as "nearly" or "substantially," are to be understood as unless there are measurement errors or inaccuracies due to manufacturing and / or production errors and, most importantly, unless there is a slight deviation from the value, measurement, shape, or geometric reference with which it is associated. For example, such terms, when associated with a value, preferably indicate a divergence of no more than 10 percent of that value. Moreover, when used, terms such as "first," "second," "top," "bottom," "main," and "secondary" do not necessarily identify an order, relationship priority, or relative position, but can simply be used to more clearly distinguish different components from each other.

[0020] Unless otherwise indicated, "perpendicular," "transverse," "parallel," or "normal," or other terms of geometric positioning between geometric elements (e.g., axes, directions, and lines) are to be understood with reference to their reciprocal geometric position between corresponding projections. Said projections are defined on a single plane parallel to the plane(s) of location of said geometric elements.

[0021] Measurements and data reported in this text are, unless otherwise indicated, to be considered as taken in ICAO International Standard Atmosphere (ISO 2533). Unless otherwise specified, as reflected in the following discussions, terms such as "processing," "computing," "determination," "computation," or the like are considered to refer to the action and / or processes of a computer or similar electronic computing device that manipulates and / or transforms data represented as physical, such as electronic quantities of records of a computer system and / or memories in, other data similarly represented as physical quantities within computer systems, records, or other information storage, transmission, or display devices.

[0022] With reference to the Figures, the motorisation device according to the invention is globally denoted by the number 1.

[0023] It is configured to be constrained, preferably jointly, to a wheelchair 10 conveniently nonmotorized. Preferably, the device 1 is constrained to the wheelchair 10 in a resolvable manner.

[0024] The wheelchair 10 can comprise, in brief, a frame 11, a posture system 12 and a moving block 13.

[0025] The posture system 12 can comprise a seat 121, usually a backrest and preferably a foot support structure. Additionally, it can comprise one or more among armrests, side rails, side supports, headrest, and side table.

[0026] The wheelchair 10 is preferably hand-pushed, so the moving block 13 is motorless.

[0027] The moving block 13 can comprise at least one wheel hinged idly to the frame 11 and defining at least one tread 13a i.e., a surface configured to contact the ground. In detail block 13 can comprise at least one rear wheel 131, in detail two, and at least one front wheel 132 in detail two.

[0028] The front wheel 132 can be pivoting wheel.

[0029] Each wheel 131 and 132 defines said tread 13a.

[0030] It can be made of elastomeric material.

[0031] The moving block 13 can comprise a handrail associated with one wheel and to be precise each rear wheel 31.

[0032] Movement block 13 can comprise at least one brake configured to stop at least one wheel 131 and 132 and thus stop the wheelchair 10.

[0033] The frame 11 is configured to support block 13 and system 12.

[0034] It can comprise one or more section bars 111 preferably with a circular crosssection. It is shown that among the section bars 111 there are first section bars corresponding to the backrest.

[0035] The one or more section bars 111 and then the frame 11 can be made of metallic material like steel.

[0036] In some cases, the wheelchair 10 can comprise a steering device 14 configured to vary the forward direction of the wheelchair 10.

[0037] The steering device 14 can comprise a structure 141 anchoring the steering device 14 to the frame 11; at least one steering wheel 142; at least one fork 143; and a hub 144 configured to bind the steering wheel 142 to the fork 143 and thus to the steering device 14 by defining an axis of rotation, suitably idler, of said steering wheel 142 relative to said fork 143.

[0038] Said axis of rotation between steering wheel 142 and said fork 143 can be parallel to the axis of rotation of other wheels 131 and / or 132.

[0039] The structure 141 can be bound in a resolvable way to the frame 11.

[0040] The fork 143 can be single-armed or double-armed.

[0041] The fork 143 can be hinged to the structure 141, appropriately in idler way, defining an additional axis of rotation substantially transverse and in detail perpendicular to the axis of rotation of the steering wheel 142 relative to the fork 143.

[0042] The steering device 14 can comprise control means 144 configured to control the rotation of the fork 143 relative to the structure 141 by varying the forward direction of wheelchair 10.

[0043] The control means 144 can be manual and, in detail, they can comprise a handlebar as shown in Fig. 1. Alternatively or additionally, they can be automatic and thus comprise a rotation control actuator between the fork 143 and the frame 141 and a control element configured to allow the user to control said actuator.

[0044] Wheelchair 10 can be of a known type.

[0045] The device 1 can comprise at least one rolling element 2 configured to go in contact with a wheel 131 and / or 132 in correspondence with the tread 13a; and at least one motor 3 kinematically connected to said at least one rolling element 2 to rotate the rolling element 2 which then controls the rotation of wheel 131 and / or 132 and thus the movement of wheelchair 10.

[0046] Preferably the device 1 comprises at least two rolling elements 2 each configured to go in contact with one of the wheels 131 and / or 132; and appropriately at least two motors 3 each associated with a rolling element 2. More preferably it comprises two rolling elements 2 each configured to contact a wheel and two motors 3 preferably operable independently of each other.

[0047] The rolling element 2 can be configured to contact a rear wheel 131.

[0048] It can comprise coating 21 realizable in high-friction material (e.g., elastomeric) so as to go in contact with the tread 13a defining between them a high coefficient of adhesion and thus avoiding their mutual slippage. In a preferred non-limiting realization example, the rolling element 2 is cylindrical and comprises a core (preferably metal) and the lining 21 covers the side surface of said core.

[0049] The rolling element 2 can comprise coating 21 realizable in high-friction material and a central body preferably made of metallic material like steel.

[0050] The motor 3 is kinematically connected to the central body of each of said at least one rolling element 2.

[0051] The motorisation device 1 can comprise a sensor unit 4 configured to detect at least one motion parameter, i.e., characterizing the movement of at least part of device 1 and thus of wheelchair 10 when device 1 is in use, i.e., associated with it; and a control board 5 configured to control the at least one motor 3 according to sensor unit 4.

[0052] The sensor unit 4 can be configured to detect the movement of part of the motorisation device 1 and, in detail, the speed of the at least one rolling element 2 and / or the at least one wheel 131 and / or 132 when the device 1 is in use. In particular, the unit 4 is configured to identify a first movement parameter such as the speed difference between the rolling elements 2 and / or between the wheels 131 and / or 132 to which the rolling elements 2 are associated allowing, for example, identification of wheel slip on mud. It can thus comprise at least one rotary sensor, appropriately identifiable in an absolute encoder, configured to detect said rotational speed.

[0053] Additionally or alternatively, the sensor unit 4 can be configured to detect the motion of the entire motorisation device 1 and specifically of wheelchair 10 when the device 1 is in use. In this case, the unit 4 is configured to identify a second motion parameter identifying the tilt, i.e., orientation, of the device 1 and consequently of the wheelchair 10 with respect to the gravitational gradient. It can comprise at least one inertial sensor appropriately such as an accelerometer and / or a gyroscope. Preferably the sensor unit 4 comprises both said at least one rotary sensor and said at least one inertial sensor.

[0054] In the case of two motors, the control board 5 can control and thus drive motors 3 asynchronously and / or synchronously.

[0055] In the case of asynchronous control of motors 3, the control board 5 can command to the motors 3 different speeds of the rolling elements 2 so as to compensate, for example, for a slip between rolling element 2 and wheel 131 or 312 or between wheel 131 or 312 and the ground. In the case of synchronous control, the board 5 can command to the two motors 3 the same speed of the rolling elements 2 and thus of the wheels compensating for, for example, an incorrect inclination of device 1 and wheelchair 10.

[0056] The control board 5 can be configured to control the at least one motor 3 in accordance with a command given by the user. For this purpose, the device 1 comprises an interface available in data connection (wired or preferably wireless) with the board. The interface can be integrated in the steering device 14 and to be precise in the control means 145 (for example in a handlebar knob).

[0057] Preferably, it is configured to control, appropriately in automatic mode, the at least one motor 3 and then the at least one rolling element 2 according to the sensor unit 4.

[0058] In detail, the control board 5 can define a normal configuration if the sensor unit 1 detects said at least one motion parameter below at least a critical threshold; and a critical configuration if the sensor unit 4 detects at least one of the one or more motion parameters at least equal to said critical threshold.

[0059] In the case of the first motion parameter, there is a first critical threshold identifying a limiting value of the difference between the acceleration (linear and / or rotational) or the velocity (linear and / or rotational) detected by the sensor unit 4 and the one defined by the motor 3. Therefore, the board 5 defines a normal configuration if the first motion parameter is less than the first critical threshold, and a critical configuration if the first motion parameter is at least equal to said first critical threshold.

[0060] In the case of second motion parameter, there is a second critical threshold identifying a limiting amplitude of the tipping angle (i.e., of tilting of the motorisation device 1 with respect to the gravitational gradient). Therefore, the control board 5 defines a normal configuration if the second motion parameter is less than the second critical threshold, and a critical configuration if the second motion parameter is at least equal to said second critical threshold.

[0061] It is pointed out that in use, as the device 1 is integral to wheelchair 10, acceleration and inclination of motorisation device 1 coincide with those of wheelchair 10.

[0062] In the normal configuration the at least one motor 3 is controllable by said interface. In the critical one the at least one motor 3 can not be controllable by said interface. In detail, in this configuration motor 3 is controlled exclusively by the control board 5 according to the sensor unit 4.

[0063] The motorisation device 1 is configured to be constrained to said wheelchair 10 solidly. It can comprise at least one constraint 6 of the device 1 to the wheelchair and specifically to the frame 11.

[0064] The constraint 6 can be configured to bind device 1 to section bar 111 and specifically to a first section bar 111.

[0065] The constraint 6 can be solvable and, for example, vice-type.

[0066] Motorisation device 1 can comprise a single supporting structure 7 to which the device components are anchored.

[0067] The supporting structure 7 can comprise tubular elements 71.

[0068] The motorisation device 1 can comprise a presser 8 configured to press the rolling element 2 against wheel 131 and / or 132 ensuring that they are in reciprocal contact. The presser 8 can comprise a carriage 81 integral to the rolling element 2; a guide 82 defining for the carriage 81 a pressure axis; and an actuator 83 configured to press the carriage 81 along the guide 82 against the wheel 131 and / or 132 when device 1 is anchored to wheelchair 10.

[0069] The actuator 83 can comprise elastic means (e.g., a compression spring) that is preloaded so that a force is exerted on the carriage 81 to pull the rolling element 2 closer to the wheel regardless of the position of the carriage 81 along the guideway 82.

[0070] Finally, the motorisation device 1 can comprise a power supply of said at least one motor. The motor 3 can be electric. Then the power supply can comprise a battery powering at least one motor 3.

[0071] The operation of the motorisation device 1 previously described in structural terms is as follows.

[0072] Initially, the motorisation device 1, taking advantage of constraints 6, is anchored to wheelchair 10 (frame 11 to be precise) in order to place the rolling elements 2 in contact with the rear wheels 131.

[0073] After the complete assembly, the sensor unit 4 detects the one or more parameters below the corresponding critical threshold, and the control board 5 commands the return to normal configuration. The user is thus able to command advancement along a path via said interface.

[0074] If, for example, while driving along a gravel road the sensor unit 4 (in this case the rotary sensor) detects a first movement parameter (i.e., a different speed between the rolling elements 2 and / or the wheels of the wheelchair 10) at least equal to the first critical threshold, the control board 5 commands to switch to a critical configuration and then it commands the motors 3 asynchronously until the first movement parameter is below the first critical threshold.

[0075] In addition, if, for example, during a climb the sensor unit 4 (in this case the inertial sensor) detects a second movement parameter (i.e., a tilt of the motorisation device 1 and thus of the wheelchair 10) at least equal to the second critical threshold, the control board 5 commands the transition to critical configuration and then it commands the motors 3 appropriately synchronously until the second movement parameter below the second critical threshold is regained.

[0076] Once all one or more parameters are below the corresponding critical threshold, the control board 5 commands a return to the normal configuration.

[0077] The motorisation device 1 according to the invention achieves important advantages.

[0078] In fact, the motorisation device 1 allows the wheelchair 10 to cope with any route without requiring special efforts and, above all, in a safe manner and to enable a user with limited / reduced upper limb mobility to easily use the wheelchair 10.

[0079] In fact, the control of motors 3 according to the inertial sensor and, in particular, the definition of the critical configuration allows the control board 5 to command the motors 3 while avoiding the tipping of wheelchair 10 or other hazards to the operator. It is pointed out that this possibility is guaranteed by the ability to command, even independently, motors 3 ensuring a quick return to the normal configuration. Another advantage is that, unlike the well-known motorized wheelchairs, device 1, being removable from wheelchair 10, does not interfere with the transportability of wheelchair 10.

[0080] An important advantage is that the mounting and operation of the motorisation device does not interfere with the functionality / usability of the wheelchair 10 and particularly with the handrails or other elements that allow a natively manual wheelchair to maintain its functionality.

[0081] A not insignificant advantage is also the simplicity of anchoring the motorisation device 1 to a wheelchair 10 and in particular also to well-known wheelchairs.

[0082] The invention is susceptible to variations within the scope of the inventive concept defined by the claims. Within that scope all details are substitutable by equivalent elements, and materials, shapes and sizes can be any.

Claims

1. Motorisation device (1) for wheelchair (10); said wheelchair (10) comprising: - a frame (11); - a posture system (12) bound to said frame (11); and - at least one wheel (131, 132) hinged idly to said frame (11) and defining a tread (13a); and characterized by the fact that said motorisation device (1) configured to be integrally bound to said wheelchair (10) and comprising - a rolling element (2) configured to go in contact with said wheel (131, 132) in correspondence with said tread (13a); - a motor (3) kinematically connected to said rolling element (2) to rotate said rolling element (2) which, then, controls the rotation of said wheel (131, 132) and thus the movement of said wheelchair (10); - a sensor unit (4) configured to detect at least one movement parameter of said motor device (1) and thus of said wheelchair (10) when said motorisation device (1) is bound to said wheelchair (10); and - a control board (5) configured to control said motor (3) according to said sensor unit (4).

2. Motorisation device (1) according to claim 1, wherein said control board (5) defines a normal configuration if said sensor unit (4) detects said motion parameter below at least a critical threshold; and a critical configuration if said sensor unit detects said motion parameter at least equal to said critical threshold.

3. Motorisation device (1) according to at least one preceding claim, wherein said motorization device (1) configured to be integrally bound to said wheelchair (10) and comprising a rolling element (2); said sensor unit (4) comprises at least one rotary sensor configured to measure an initial motion parameter identifying the difference in rotational speed between and said wheel (131, 132).

4. Motorisation device (1) according to at least one preceding claim, wherein said sensor unit (4) comprises at least one inertial sensor configured to measure a second motion parameter identifying the inclination of said motorisation device (1) with respect to gravitational gradient.

5. Motorisation device (1) according to at least one preceding claim, comprising a presser (8) configured to press said rolling element (2) against said wheel (131, 132) ensuring a reciprocal contact between pressing said rolling element (2) and said wheel (131, 132).

6. Motorisation device (1) according to claim 5, in ci said presser (8) comprises a carriage (81) integral to said rolling element (2); a guide (82) defining for said carriage (81) a pressure axis; and an actuator (83) configured to press said carriage (81) along said guide (82) against said wheel (131, 132).

7. Motorisation device (1) according to at least one preceding claim, wherein said rolling element (2) comprises a coating (21) realizable in high-friction material and a central body made of metallic material; and wherein said motor (3) is kinematically connected to said central body of said rolling element (2)8. Wheelchair (10) comprising a motor device (1) according to at least one previous claim.

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