Drive device for a manually operated wheelchair

Abstract

The present invention relates to a drive device for a wheelchair especially a manually operated wheelchair and the drive device is adapted to provide a drive function when operated by a user seated in the wheelchair. Also, the present invention relates to an add-on drive device for wheelchairs and to a wheelchair comprising such an add-on device, which may be mounted on a wheel or the rim of a wheel of a manually operated wheelchair. Especially, the invention relates to a drive device for a manually operated wheelchair comprising a handle (1) which during operation moves back and forth between a first position and a second position during operation i.e. when propelling the wheelchair either forward or backward, the handle (1) being connected to a gear unit (7) by a coupling (11) and the gear unit (7) is coupled or fixed to a wheel hub or wheel of the manually operated wheelchair, wherein the drive device comprises a handle part (A) comprising the handle (1) and primary fastening means (5), and a fixed part (B) being fixed to or constituting a part of the wheel hub or wheel and comprising secondary fastening means (6) corresponding to the primary fastening means (5) of the handle part (A), which primary and secondary fastening means (5, 6) are releasably joined during operation.

Description

Drive device for a manually operated wheelchairThe present invention relates to a drive device for a wheelchair especially a manually operated wheelchair and the drive device is adapted to provide a drive function when operated by a user seated in the wheelchair.Also, the present invention relates to an add-on drive device for wheelchairs which may be mounted on a wheel or the rim of a wheel of a manually operated wheelchair.Background of the inventionIn general, a manual wheelchair is understood to be a wheelchair where the user is seated during use and driving the wheelchair forward by use of the arms. Traditionally, a manual wheelchair is propelled by the seated user by pushing or pulling directly on a drive rim of the wheel.Shoulder pains are a common problem that many users of traditional manual wheelchairs face. Shoulder pain may negatively impact functional independence, physical activity levels and quality of life of those affected, and it has been reported that people with paraplegia, which is a spinal cord injury below the first thoracic vertebra, experience shoulder pain as a limiting factor when performing activities of daily living, such as wheelchair propulsion, transfers, reaching overhead, and lifting. Since manual wheelchair users are reliant on their upper extremities for mobility and activities of daily living, they cannot just simply avoid involvement of the shoulders while recovering, and preservation of shoulder function is therefore of great importance.Shoulder pains experienced by manual wheelchair users are believed to be caused by an increase in biomechanical demands. As using the shoulder joints becomes more painful, manual wheelchair users tend to use the shoulders less for mobility, making the manual wheelchair user less physically active, potentially resulting in decrease of their physical capacity over time both in terms of endurance and strength.Beside increased biomechanical load on the shoulder joint, the shoulder pains might also be caused by muscle strength imbalance which may lead to rotator cuff impingement. Wheelchair propulsion is a push-dominant movement, relying on the anterior shoulder muscles and the chest muscles. Accordingly, muscle strength imbalances have been reported in manual wheelchair users, compared to people without disability, in which posterior muscles were shown to be weaker relative to the anterior muscles, when testing shoulder adduction and pulling strength.Strengthening the relatively weaker posterior muscles, as well as stretching the relatively stronger anterior muscles, has been shown to reduce shoulder pain among manual wheelchair users in as short a time frame as 8 weeks, with a common strength exercise being scapular retraction, which is a pull motion sharing many similarities with a rowing motion in terms of retractor activation. Therefore, exercises focusing on pull motions, working the relatively weaker posterior muscles, might reduce shoulder pain over time.It has been suggested to reverse the propulsion pattern by converting a conventional wheelchair push-motion into a pulling motion. Such a mechanism is produced by thecompany Rowheel (Madison, Wisconsin, USA) and the mechanism is a mechanical add-on to a standard manual wheelchair, where the standard drive wheels are swapped with Rowheel drive wheels. The Rowheel drive wheels allow the user to pull a drive rim on the wheelchair wheels creating a forward motion, and a planetary gear system propels the wheelchair forward. However, the Rowheel system lacks flexibility as it only works by using a pull motion for forward propulsion when using the drive rim. To switch back to a push motion, and working the anterior muscles again, the Rowheel drive wheels must be swapped back to the standard drive wheels.US 2009 / 0051138 Al discloses a motion control system for lever propulsion of a wheelchair which motion control system enables a number of different manipulations at the hand grip of the lever. As many as five user-controlled operations may be performed without need to remove a hand from the hand grip. A user applies force to the hand grip to initiate the motion lever in its forward and rearward strokes. In addition, the hand grip may be pivoted relative to the lever to control a brake. A parking brake mechanism may be provided at the hand grip to apply constant brake force. The direction shifter at the top of the hand grip may be used to shift between forward, neutral and rearward modes of operation. Also, steering of a front caster wheel is possible by rotating the hand grip and the power applied per lever stroke is adjustable.US 2008 / 238022 Al discloses a drive mechanism for a lever propulsion wheelchair including at least one clutch and at least one gear set contained within a central hub housing operatively coupled to the drive surface of the main wheel being driven. There may be additional clutches and gear sets contained within the hub housing and coaxial to the wheel. By locating the transmission components within the hub housing and providing the coaxial arrangement, various user capabilities may be enabled without increasing the wheelchair width, as compared to the width of conventional pushrim propulsion wheelchairs. Transmission components are cooperatively arranged to provide capabilities that may include forward, rearward and neutral "gears," braking, anti-rollback, and quick-release removal. It is mentioned in the document (

[0013] ) that by locating the transmission components within the wheel hub housing, the drive mechanism can be easily retrofit to a conventional wheelchair and can be readily added to and removed from the wheelchair. However, it is not possible to add or remove the lever and the transmission components without removing the wheels of the wheelchair and therefore it is not possible to remove the lever drive mechanism while a user is positioned in the wheelchair.WO 2005 / 025973 Al relates to a propulsion apparatus (20) to be mounted to a wheel (8) or to be integrally formed with a wheel of e.g. of a wheelchair. The propulsion apparatus (20) has a first portion to be statically attached to either a rim of the wheel (8) or structural member being rigidly attached to the wheel (8) and projecting therefrom. The propulsion apparatus (20) also has a second portion (23) being pivotal about the rotational axis of the wheel (8). Furthermore, the propulsion apparatus (20) comprises coupling means which are interposed between the first and second portions so that when the second portion (23) is rotated about the axis of the wheel (8) it causes the first portion, and therefore also thewheel (8), to rotate. However, the propulsion device does not allow a user to pull when propelling the wheelchair forward.The pull function devices according to the above-mentioned documents are build-in devices which cannot be added to or removed from a wheelchair without removing the wheels and making technical changes to the wheelchair.Hence, an improved add-on for a manual wheelchair making it possible for the user to switch between pulling and pushing movements as often as needed would be advantageous to reduce muscle strength imbalance and shoulder pains and improve functional independence.Summary of the inventionThus, an object of the present invention relates to providing a drive device which may reduce or remove shoulder pains for a user of a manual wheelchair.Thus, a first aspect of the invention relates to drive device for a manually operated wheelchair comprising a handle (1) which during operation moves back and forth between a first position and a second position during operation i.e. when propelling the wheelchair either forward or backward, the handle (1) being connected to a gear unit (7) by a coupling (11) and the gear unit (7) is coupled or fixed to a wheel hub or wheel of the manually operated wheelchair, the drive device comprises a handle part (A) comprising the handle (1) and primary fastening means (5), and a fixed part (B) being fixed to or constituting a part of the wheel hub or wheel and comprising secondary fastening means (6) corresponding to the primary fastening means (5) of the handle part (A), which primary and secondary fastening means (5, 6) are releasably joined during operation.That the primary and secondary fastening means (5, 6) are releasably joined during operation means that the handle part (A) comprising the primary fastening means (5) may be detached and removed from the secondary fastening means (6), preferably in a direction perpendicular to the forward direction of the wheelchair, and from the wheel.When the handle part (A) is removed it may be possible for a user seated in the wheelchair to apply traditional propelling of the wheels by pushing and pulling directly on the wheels without removing the fixed part (B). The handle part (A) may be re-attached in order for the user of the wheelchair to use the functionality of the handle part (A) when propelling the wheelchair. I.e., the releasable attachment of the handle part (A) makes it possible for the user to switch easily between different propelling modes and different loading of arms and shoulders.According to any embodiment of the first aspect of the invention, the handle (1) may comprise a piece extending in an upward direction from the wheel hub during operation, and the handle (1) moves between a first and second position which first and second positions are interrelated in a V-shape.According to any embodiment of the first aspect of the invention, the gear unit (7) may comprise input means (7b) such as a gear wheel and output means (7a) such as a gear wheel where the input means (7b) are mechanically connected to the handle (1) and drivenby the handle (1) whereas the output means (7a) are mechanically connected to a wheel of a manually operated wheelchair and drive this wheel.According to any embodiment of the first aspect of the invention, the gear unit (7) may be configured to change the direction of rotation in such a way that input means (7b) are rotated in a first rotational direction and output means (7a) are rotated in a second rotational direction, and intermediate means (7c) translate the rotational direction of the input means (7b) into the rotational direction of the output means (7a).According to any embodiment of the first aspect of the invention, the gear unit (7) comprising input means (7b) and output means (7a) may be a bevel gear or a planet gear.According to any embodiment of the first aspect of the invention, the gear or gear part (7a) may constitute a part of the wheel of the wheelchair and may be coaxial with a rotatable coupling part of the handle part (A) during operation i.e. when the corresponding primary (5) and secondary (6) fastening means are joined.According to any embodiment of the first aspect of the invention, the gear or gear part (7a) may constitute a part of the handle part (A) and may be positioned coaxial with the stationary rotation axis (4) of the wheelchair wheel during operation, i.e. when the corresponding primary (5) and secondary (6) fastening means are joined.In general, a wheel hub constitutes a central part of the wheel, and the wheel hub is rotated with the wheel. The wheel hub rotates around a stationary rotation axis (4) which constitutes a part of or is fastened to the wheelchair. In general, the rotation axis (4) does not rotate, the rotation axis (4) constitutes a centre which the wheel rotates around.According to any embodiment of the first aspect of the invention, the corresponding primary and secondary fastening means (5, 6) of respectively the handle part (A) and the fixed part (B) may be constituted by magnets either partly or completely.According to any embodiment of the first aspect of the invention, the corresponding primary and secondary fastening means (5, 6) of respectively the handle part (A) and the fixed part (B) may be constituted by releasable click-parts either partly or completely.According to any embodiment of the first aspect of the invention, the primary fastening means (5) may be configured to attach the handle part (A) to an outer end or outer surface of the wheel or wheel hub, where "outer" means that the end or surface of the wheel or wheel hub faces away from a seated user.According to any embodiment of the first aspect of the invention, the handle part (A) may extend from a central point of the wheel to a length of minimum 0,20 m, or a length of minimum of 0,30 m, and / or to a maximum of 0,90 m, or at maximum 0,80m or at maximum 0,70 m.According to any embodiment of the first aspect of the invention, the handle part (A) may comprise a switch mechanism (8, 9, 10) configured to switch between at least two, or at least three or more different operational modes, which operational modes are defined as- a first mode where the wheel is rotated, and the wheelchair is propelled forward when the handle (1) is moved in the first direction, whereas there is no load on the handle (1) when the handle (1) is moved in the second direction, and- a second mode where the wheel is rotated, and the wheelchair is propelled backward when the handle (1) is moved in the second direction, whereas there is no load on the handle (1) when the handle (1) is moved in the first direction.Optionally, the first direction may be backward i.e. the handle (1) is pulled towards the user, and the second direction may be forward i.e. the handle (1) is pushed away from the user.According to any embodiment of the first aspect of the invention comprising a switch mechanism, the switch mechanism (8, 9, 10) may be configured to switch between at least three or more different operational modes, where a third operational mode is a neutral mode in which mode the wheel is not rotated by moving the handle (1), neither when the handle (1) is moved in the first direction, nor when the handle (1) is moved in the second direction.According to any embodiment of the first aspect of the invention comprising a switch mechanism, the switch mechanism may comprise locking means (10) and an actuating mechanism (9), which actuating mechanism (9) is configured to be activated by the user and either activate (lock) or deactivate (unlock) the locking mechanism (10) to choose an operational mode.According to any embodiment of the first aspect of the invention comprising a switch mechanism, the switch mechanism may comprise at least two rotating parts (8) each rotating part (8) configured to be locked or unlocked by locking means (10). Optionally, at least one of or all the rotating part (8) may comprise either a one-way clutch or a rachet mechanism.According to any embodiment of the first aspect of the invention comprising a switch mechanism, the at least two rotating parts (8) may be positioned on either one common rotation axis (16) or on two separate rotation axis (16).According to any embodiment of the first aspect of the invention, the corresponding primary and secondary fastening means (5, 6) of respectively the handle part (A) and the fixed part (B) may be positioned at least at two opposite positions along a perimeter of the wheel hub or rotation axis (4), optionally at three, four or more position at a perimeter of the wheel hub or rotation axis (4), optionally the secondary fastening means (6) are ring-shaped comprising openings and the primary fastening means (5) comprises protruding pins or screws.According to a second aspect of the invention, the invention relates to a wheelchair comprising a fixed part (B) fixed to or constituting a part of a wheel hub or a wheel and comprising secondary fastening means (6) corresponding to primary fastening means (5) of a handle part (A) of a drive device according to the first aspect of the invention.Brief description of the figuresFigure 1 shows a side view of a first embodiment of an add-on drive device according to the invention.Figure 2 shows a front view of the first embodiment of an add-on drive device according to the invention.Figure 3 shows a back side view of the first embodiment of an add-on drive device according to the invention.Figure 4 shows an embodiment of a fixed part B of an add-on drive device according to the invention.Figure 5 shows a first embodiment of a coupling of the embodiment shown in figs. 1-3.Figure 6 shows a second embodiment of a coupling of the embodiment shown in figs. 1-3.Figures 7A, 7B and 7C shows an enlargement of a two rotating parts shown respectively from the back side, the front and in exploded form.Figure 8 shows a second embodiment of the fixed part B of an add-on drive device according to the invention.Figure 9 shows the second embodiment of the fixed part B shown in a front view.Figure 10 shows the second embodiment of the fixed part B in a front view without the power transfer part / secondary fastening means.Figure 11 shows a third embodiment of the fixed part B of an add-on drive device according to the invention.Figure 12 shows the third embodiment of the fixed part B shown in a front view without the power transfer part / secondary fastening means.Figure 13 shows the third embodiment of the fixed part B in a front view without the planet carrier revealing the planet gear.Figure 14A and 14B respectively shows a second embodiment of an add-on drive device according to the invention.Figure 15 shows an embodiment of a handle part A comprising a switch mechanism with a single common rotation axis for two rotating parts.Figure 16A and 16B respectively shows an embodiment of a switch mechanism comprising a single and common rotation axis comprising two rotating parts and a locking mechanism.The present invention will now be described in more detail in the following.Detailed description of the inventionDefinitionsPrior to discussing the present invention in further details, the following terms and conventions will first be defined :In general - when this expression is used when mentioning a feature relating to the present invention, it must be understood that the feature may be used with all embodiments of the invention, even if the mentioning is made in the detailed part of the document.Figures 1, 2 and 3 disclose a first embodiment of a drive device according to the invention. Fig. 1 shows a side view of the drive device comprising both a handle part A (left) and a fixed part B (middle) which side view shows a rotation axis 4 of a not shown wheel of the wheelchair. In general, the rotation axis 4 does not rotate and the rotation axis 4 is positioned inside a wheel hub of the wheelchair wheel. The rotation axis 4 may be fixed to the wheelchair frame at an inner end 15 which according to this embodiment is shown as a thread and thereby secures the wheel of the wheelchair to the not-shown frame. In general, the rotation axis 4 comprises fixing means preventing the rotation axis 4 from rotating relative the wheelchair frame.Fig. 2 shows a view of the front side of the handle part A without front panel, the front side of the handle part A of this embodiment faces the surroundings and faces away from the wheel during operation.Fig. 3 shows a back side view of the handle part A (without the fixed part B) which back side view faces away from the surroundings and faces the wheel during operation.In general, a drive device according to the invention comprises a handle part A comprising a handle 1 and primary fastening means 5, and a fixed part B, which is either fixed to the wheel hub or the wheel or constitutes a part of the wheel hub or the wheel, and comprises secondary fastening means 6a, 6b corresponding to the primary fastening means 5 of the handle part A, which primary and secondary fastening means are releasably attached to each other during operation."During operation" defines a situation or state where the handle part A is attached to the fixed part B by joining or attaching or combining the primary fastening means 5 of the handle part A to / with the secondary fastening means 6a, 6b of the fixed part B and where a user seated in the wheelchair may propel the wheelchair either forward or backward.In general, a user may be seated in the wheelchair while joining or attaching or removing or releasing the handle part A to or from the fixed part B meaning that the wheel to which the handle part A is being attached is upright and operational e.g. by standing on the ground when attaching or removing the handle part A.Normally, the handle part A comprises a housing 2 providing a closed space for the moving parts of the handle part A which housing 2 shields the surroundings from the moving parts so that the user or the surroundings do not get into contact with the moving parts duringoperation. The housing 2 also shields the moving parts from the surroundings preventing dust, water, and dirt from interfering with the working of the moving parts.In general, the handle 1 is during operation, i.e. when propelling the wheelchair either forward or backward, moved back and forth between a first and a second position.The handle 1 may be configured to a vertical grip as shown with the embodiment of figs. 1-3 where the thumb points upward during use, or to a not-shown horizontal grip i.e. where the thumb points either left or right during use, or it may be configured to an intermediate or inclined grip between horizontal and vertical.In the shown embodiment, the handle 1 has the form of a straight piece extending in a more or less vertical direction and during operation the handle 1 moves between a first and second position interrelated in a V-shape where the wheel hub or rotation axis 4 constitutes the centre or the lowest point of the V-shape. Alternatively, the handle 1 may have the shape of a e.g. a ring or another closed perimeter which might be easier for a user to hold on to especially for a user having reduced dexterity, and the handle 1 may alternatively be positioned horizontally during use or at an angle between vertical and horizontal.The handle part A of the drive device comprises primary fastening means 5 used to fasten the handle part A to the fixed part B and consequently to the wheel during use.In general, it is preferably possible to remove the handle part A from wheel without using any tool. In order not to interfere with the operational direction of the handle part A which is normally back-and-forth in the moving direction of the wheel, the primary and secondary fastening parts are configured such that the handle part A may be removed from the operational position and from the secondary fastening means 6a, 6b by moving the handle part A in an orthogonal direction to the back-and-forth moving direction, i.e. the handle part A may be pulled to the side when removed in a direction substantially parallel to the rotation axis 4.In general, the primary fastening means 5 of the handle part A and the corresponding secondary fastening means 6, 6a of the fixed part B may comprise corresponding primary surfaces 23a, 23b parallel to each other and fitted to slide relative to each other in a direction approximately perpendicular to the direction of moving the handle A relative to the wheel. The moving direction of the handle A is normally back and forth relative to the direction of moving / driving and consequently a direction being perpendicular to the direction of moving the handle relative to the wheel may be parallel to the rotation axis 4.Also, the primary fastening means 5 and the corresponding secondary fastening means 6, 6a respectively may comprise surfaces 23a, 23b which extend in a direction or dimension being at least partly parallel to the direction of movement of the handle A and perpendicular to the direction of the rotation axis 4 of the wheel, in such a way that the force transmitted to the handle A during operation is transmitted through these corresponding surfaces 23a, 23b.The corresponding primary and secondary fastening means 5, 6, 6a may comprise or be constituted of protruding parts such as cylinders fitting into openings of corresponding shape where the side surfaces define the insertion direction which is e.g. perpendicular to thedirection of moving the handle A, or they may be constituted of plates comprising cut-outs corresponding to corresponding protruding parts of a neighbouring surface.In general, the corresponding primary and secondary fastening means 5, 6 may be secured in a fixed or attached position by releasable means such as magnets or click-parts. That the means are releasable, means that it is possible to remove and re-attach the handle part A, preferably without using tools.In general, the primary fastening means 5 may be configured to attach or fix the handle part A to an outer end or to an outer surface of the wheel or the wheel hub. In this context "outer" defines an end or a surface of the wheel or wheel hub which faces away from a seated user, i.e. the wheel comprising rim and spokes is positioned between the seated user and the handle part A. This mounting or attachment position of the handle part A allows for easy attachment and detachment of the handle part A as no part of the wheelchair prevents that the handle part A is moved away from the wheel. It is therefore not necessary to remove the wheel from the wheelchair to detach the handle part A and it may be possible to remove the handle part A without the user having to get out of the wheelchair. Also, after having removed the handle part A, the user may control and propel the wheelchair in a traditional way by gripping the wheels without being disturbed by the upright handles 1.As illustrated in fig. 1, the fixed part B may be fixed to the wheel hub between the spokes and e.g. to a side of the wheel hub between the spokes being closest to the handle part A. The fixed part B may be fixed on a permanent form where "permanent form" means that it cannot be removed without using tools and without removing the wheel from an operational position. Alternatively, the fixed part B may be constituted by a part of the wheel, and it may then not be possible to remove the fixed part B from the wheel without destroying the wheel. E.g., the fixed part B may be fastened by screws or similar positioning means requiring a tool for mounting which positioning means can keep the fixed part B in a desired position, not only when the handle part A is mounted on the wheelchair but also when the handle part A has been removed from the wheelchair. Alternatively, the fixed part B may be positioned permanently during construction of the wheel e.g. during a moulding process or by gluing or welding.A fixed part B may be relatively small, i.e. in general, the fixed part B does normally not extend beyond the rim of the wheel, and having the fixed part B permanently mounted on the wheel will therefore not limit or prevent a user's possibilities for controlling and propelling the wheelchair by handling the wheels of the wheelchair directly.Figure 4 illustrates an embodiment of a fixed part B which may be used according the first embodiment.This embodiment of the fixed part B comprises a ring-shaped part constituted of two half parts joined with screws 6b. The ring-shaped part comprises secondary fastening means 6a in shaped as eight cylindrical openings corresponding to the eight protruding cylindrical parts 5 of the handle part A shown in fig. 3 and each opening 6a comprises outer contact surfaces 23b. The two half-parts may be fixed around the wheel hub. The fixed part B may beattached to the wheel before the drive device is put to use and may be left in the attached position regardless of whether the handle part A of the drive device is mounted or not.In general, the corresponding primary and secondary fastening means 5, 6, 6a of respectively the handle part A and the fixed part B may partly or completely comprise or be constituted of corresponding magnetic parts of opposite polarity.Alternatively, the corresponding primary and secondary fastening means 5, 6, 6a of respectively the handle part A and the fixed part B may in general comprise or be constituted of corresponding click-parts which corresponding parts fits when sliding into position and lock releasably when in a final position.According to one embodiment, the corresponding primary and secondary fastening means 5, 6a of respectively the handle part A and the fixed part B may comprise a combination of one or more protruding parts and magnetic parts, i.e. magnetic parts are placed on protruding parts facing openings or areas comprising magnetic parts with opposite polarity.The primary fastening means 5 of the handle part A may comprise or be constituted of one or more discrete units distributed around the rotation axis 4 or around a position for receiving the rotation axis 4 on a ring-shaped unit. According to the embodiment shown in fig. 3, the primary fastening means comprises eight discrete protruding units 5 distributed evenly in a circle around a square opening 12 which opening 12 is adapted to receive the outer end of the rotation axis 4 during operation.In general, the secondary fastening means 6a of the fixed part B correspond in shape and position to the primary fastening means.According to the first embodiment, the corresponding magnets constituting or being part of the secondary fastening means 6a may be ring-shaped or the corresponding magnets may be shaped as one, two or more discrete areas e.g. in form points.In general, a drive device according to the invention comprises a switch mechanism and the switch mechanism may switch an operational mode of the drive device between at least two or optional three, modes:- In a first mode, the wheel is rotated, and the wheelchair is propelled forward when the handle 1 is pulled backward, whereas there is no load on the handle 1 when the handle 1 is pushed forward.- In a second mode, there is no load on the handle 1 when the handle 1 is pulled backward, whereas the wheel is rotated, and the wheelchair is propelled backward when the handle 1 is pushed forward.- In an optional third mode, the handle 1 is not loaded neither when pushing the handle 1 forward nor when pulling the handle 1 backward, this third state may be used if a helper is pushing the wheelchair.The purpose of the switch mechanism is to make the user able to change the operation mode, the switch between operation modes may be controlled by the user self without the need to involve a third party. Preferably, the switch between operation modes is done byactuating an actuator 3 e.g. by pushing a button with a thumb, when the handle 1 is configured to a vertical grip, the actuator 3 may then be positioned at the upper or outer end of the handle 1.In general, the switch mechanism may comprise at least two rotating parts 8 mounted either on one common rotating axis 16 or on two or more separate rotating axis 16.In general, each rotating axis 16 is able to rotate in two directions. Positioning two rotating parts 8 on the same rotation axis 16 makes it possible to provide a robust unit and to reduce the dimensions of the handle part A.In general, each rotating part 8 may rotate in one directions and may be prevented from rotating in the other direction. Each rotating part 8 may e.g. comprise or be constituted of a one-way clutch or a rachet.The switch mechanism also comprises an actuating mechanism 9 comprising or configured to operationally connect to and control position or state of a locking means 10 which locking means 10 in one position or in one state allows rotation of a rotating part 8 in a first direction and in a second position or state prevents rotation of a rotating part 8 or prevents rotation of a rotating part 8 in the first direction, and a coupling 11 configured to mechanically coupling the rotation of each rotating parts 8 to a gear unit 7 either directly by providing an interaction between the rotating part 8 and a rotating part 7b of the gear unit 7 or indirectly by providing an interaction between a separate part such as a chain or belt which separate part interacts with a rotating part 7b of the gear unit 7.In general, a gear unit 7 according to the invention comprises input means, such as a power transfer part 7b which input means is connected to and controlled or driven by a rotating part 8, and output means such as a gear 7a, which is operationally connected to and configured to rotate the wheel.Normally or in general, the gear unit 7 comprises input means 7b, intermediate means 7c and output means 7a. The gear unit 7 is configured to change the direction of rotation so that the rotating part 8 rotates in a first rotational direction and the rotating part 8 is configured to transfer this rotation to the input means 7b of the gear unit 7, the input means 7b of the gear unit 7 in connection or combination with intermediate means 7c translate the rotation of the input means 7b into a rotation of the output means 7a and the rotation of the output means 7a defines the rotation of the wheel.Many different and well-known gear units 7 may be used with the invention, a skilled person will be able to construct and adapt a gear mechanism which functions as desired.Fig. 2 shows a front view of a handle part A of a first embodiment. The handle part A is shown without a front panel which makes it possible to see the operational parts of the handle part A according to the invention. The gear unit 7 of the first embodiment shown in figs. 1-3 comprises a bevel gear comprising a transfer part 7b operationally connected to the rotating parts 8, a rotating part 7a fixed to the wheel hub, an intermediate means 7c constituted of four gear wheels translating the rotation from the transfer part 7b to arotation of the rotating part 7a and the wheel. The complete gear unit 7 is positioned in the handle part A.The bevel gear of the first embodiment is able to transmit motions between a first angular or intersecting shaft extending in the direction of the handle 1 to second shaft defined by a line through the rotation axis 4 around which line the wheel or wheel hub rotates.The gear 7a is at one side fixed or connected to primary fastening means 5 and on the opposite side operationally connected to the input means in form of the power transfer part 7b. The rotation of transfer part 7b is provided through the coupling 11 which coupling 11 according to this embodiment comprises a chain and depends on the mode set by the switch mechanism which switch mechanism is illustrated in figs. 7A-7C, and the switch mechanism is embedded in the housing 2. Power transfer part 7b is therefore driven by the handle 1, and the propulsion direction is controlled by the state of the switch mechanism.Figures 7A, 7B and 7C illustrates the switch mechanism of the first embodiment which switch mechanism comprises two rotating parts 8 positioned on two different rotation axis 16. In general, each rotating part 8 comprises a drive wheel 13 which is configured to rotate freely, i.e. without transferring power or load to the gear, in both directions if the rotating part 8 is unlocked by the locking means 10 and configured to transfer power or load when rotated in one direction if the rotating part 8 is locked by the locking means 10.In order to transfer power when rotated in one direction, each rotating part 8 may e.g. comprise a rachet mechanism or a one-way clutch 17.The embodiment of a rotating part 8 shown in figs. 5, 6 and 7A-7C comprises a one-way clutch. The one-way clutch comprises an outer ring and an inner ring and a rotation axis 16 which rotates freely in both directions, the one-way clutch 17 is attached to the outer surface of the rotation axis 16. Each rotating part 8 further comprises a drive wheel 13 and a pin lock wheel 14. The outer ring of the one-way clutch 17 can only rotate in one direction relative to the inner ring of the one-way clutch 17, as the inner ring of the one-way clutch 17 is fastened to the outer surface of the rotation axis 16, the one-way clutch 17 may rotate in both directions together with the rotation axis 16 as long as the outer ring of the one-way clutch 17 is not prevented from rotating. The drive wheel 13 is fastened to an adapter unit 19 with bolts 18, and the adapter unit 19 is locked to the inner ring of the one-way clutch17. The drive wheel 13 and the pin lock wheel 14 are locked by locking means relative to respectively the inner ring and the outer ring of the one-way clutch 17 in such a way that the drive wheel 13 and the pin lock wheel 14 rotates in the same manner as respectively the inner and the outer ring of the one-way clutch 17 to which they are locked. The drive wheels 13 of the two one-way clutches 17 are both functionally connected to the power transfer part 7b of the gear unit 7 via coupling 11. If the pin lock wheel 14 of a first one-way clutch 17 is locked, the coupling mechanism 11 may only transfer power to the gear unit 7 if the handle 1 is pushed forward, if the pin lock wheel 14 of a second one-way clutch is locked then the coupling mechanism 11 may only transfer power to the gear unit 7 when the handle 1 is pulled backward.Figures 5 and 6 illustrate two different embodiments of a coupling 11.According to the embodiment of fig. 5, the coupling 11 comprises a chain which chain connects the drive wheels 13 of the two rotating parts 8 with the power transfer part 7b of the gear unit 7. According to the embodiment of fig. 6, the drive wheel 13 of each of the rotating parts 8 is directly connected to and interacting with the power transfer part 7b of the gear 7 i.e. the coupling 11 is constituted of the interacting teethes of the wheels 13 and 7b.Figures 8, 9 and 10 show a second embodiment of a fixed part B. According to this embodiment, the gear unit 7 is built into or positioned inside or in connection with the wheel or the wheel hub of the wheelchair.Fig. 8 shows a side view of a wheel hub where spokes of the wheel may be mounted on each side of the central wheel hub 20 and the gear part 7a - which is not shown in fig. 8 or 9 but the position of the gear part 7a is indicated with an arrow - is positioned inside the wheel hub or in close connection with the wheel hub 20 closest to the outer end of the rotation axis 4. The fixed part B comprises a planetary gear as the gear part 7a. The button of the outer end of the rotation axis 4 is a quick release button which may be activated in order to remove the wheel from the wheelchair. The outer cover plate which is seen in fig. 8 and fig. 9 constitutes the power transfer part 7b and the secondary fastening means 6 are provided as openings along the periphery of the power transfer part 7b.Figure 9 shows the same part of same embodiment as fig. 8 from a different angle. From this view, it is also possible to see the power transfer part 7b through which power is transferred from the handle 1 of a handle part A when such a handle part A is attached to the secondary fastening means 6. If the complete plate constituting the power transfer part 7b is constituted of a magnetic material or the plate comprises magnetic areas, then these magnetic parts may constitute or contribute to the secondary fastening means 6 which correspond to primary fastening means 5 of a handle part A.Figure 10 shows the same embodiment as fig. 9 but the power transfer part 7b is removed thereby allowing a view to the planetary gear part 7a positioned in connection with the wheel hub 20. The planetary gear is a traditional planetary gear comprising an outer ring gear (driving gear), a central sun gear (driven gear) and interacting planet gears attached by a planet carrier.Figures 11, 12 and 13 show a third embodiment of a fixed part B. According to this embodiment, the gear unit 7 is also built into the wheel or into the wheel hub of the wheelchair.Fig. 11 shows a front-side view of a wheel hub where spokes of the wheel may be mounted on each side of the central wheel hub 20 and the gear part 7a is positioned inside the wheel hub or in close connection with the wheel hub 20 closest to the outer end of the rotation axis 4. The fixed part B comprises a planetary gear as the gear part 7a. The button of the outer end of the rotation axis 4 is a quick release button which may be activated in order to remove the wheel from the wheelchair.Fig. 12 shows the same part of same embodiment as fig. 11 where the power transfer part 7b has been removed to allow a view to the inside of the wheel hub. From this view, it is also possible to see a gear part 7a and a plate connecting and fixing the intermediate means 7c.Fig. 13 shows the same embodiment as fig. 11 and 12 but the plate connecting and fixing the intermediate means 7c has been removed. The planetary gear 7a is a traditional planetary gear comprising an outer ring gear (driving gear), a central sun gear (driven gear) and interacting planet gears attached by a planet carrier.Figures 14A and 14B show a second embodiment of a handle part A according to the invention.Fig. 14A shows a view of the front side of the handle part A without a front panel, the front side of the handle part A normally faces the surroundings and faces away from the wheel during operation.Fig. 14B shows a view of the front side of the same handle part A as fig. 14A where the inside of the embodiment is covered by the front panel which is constituting a part of the housing 2.The second embodiment of the handle part A comprises the same operational or functional parts as the first embodiment and the parts of the second embodiments therefore have the same reference numbers as in the first embodiment. However, the operational parts of the second embodiment are positioned differently, and the different position makes it possible to provide a slimmer and more elegant design of the handle part A.Instead of positioning the rotating parts 8 on each their rotation axis 16 symmetrically above the power transfer part 7b, the power transfer part 7b is positioned closer to a lower rotating part 8 than to an upper rotating part 8.The coupling 11 is constituted of a chain mechanically connecting the rotating parts 8 and the power transfer part 7b, and the chain of this embodiment is connected to a coupling tightening wheel 21 which pushes against the coupling 11 in order to tighten the coupling and obtain a precise transfer of power between the rotating parts 8 and the power transfer part 7b.Also in this embodiment, the handle 1 has the form of a straight piece extending in an upward direction which during operation moves between a first and second position interrelated in a V-shape.Connecting means 22 constitutes a connection between the actuator 3 and the switch mechanism comprising the actuator means 9 and the locking means 10. The connecting means 22 may comprise a line or a chain which allows transfer of signals from the actuator 3 to the switch mechanism.The actuator 3 may comprise a button extending from the top of the handle 1 may be operated by a thumb and may have three positions. The three positions may comprise a first position where the actuator is not actuated i.e. unloaded, a second position where theactuator is fully actuated i.e. fully loaded, and a third position which is an intermediate position between the not-actuated and the fully-actuated position.Figure 15 shows yet an embodiment of a handle part A comprising an embodiment of a switch mechanism comprises two rotating parts 8 positioned on a common rotation axis 16. Each rotating part 8 comprising either a ratchet mechanism or a one-way clutches and are mounted on one common rotation axis 16. In fig. 15, it is illustrated how the locking means 10 are connected to an actuator 3 at the top of the handle 1 by connecting means 22, making it possible for the user to determine the mode of the switch mechanism.Figures 16A and 16B illustrate the switch mechanism of fig. 15 in further details. The actuating means 9 of this embodiment is constituted of a toothed wheel which simultaneously moves one locking means in one direction and the second locking means 10 in the opposite direction.Fig. 16A shows the switch mechanism in a first mode, where the wheelchair is propelled forward when the handle 1 is forced in a first direction e.g. backward, whereas there is no load on the handle 1 when the handle 1 is pushed in the second direction e.g. forward.Fig. 16B shows the switch mechanism in a second mode, where the wheelchair is propelled backward, in this mode there is no load on the handle 1 when the handle 1 is forced in the first direction e.g. backward, and the wheelchair is propelled backward when the handle 1 is forced in the second direction e.g. forward.The switch mechanism may have a third state, where the handle 1 is not loaded neither when pushing the handle 1 forward nor when pulling the handle 1 backward.

Claims

Claims1. A drive device for a manually operated wheelchair comprising- a handle (1) which during operation moves back and forth between a first position and a second position during operation i.e. when propelling the wheelchair either forward or backward, the handle (1) being connected to a gear unit (7) by a coupling (11) and the gear unit (7) is coupled or fixed to a wheel hub or wheel of the manually operated wheelchair, characterized in that the drive device comprises- a handle part (A) comprising the handle (1) and primary fastening means (5), and- a fixed part (B) being fixed to or constituting a part of the wheel hub or wheel and comprising secondary fastening means (6) corresponding to the primary fastening means (5) of the handle part (A), which primary and secondary fastening means (5, 6) are releasably joined during operation.

2. A drive device according to claim 1, wherein the handle (1) comprises a piece extending in an upward direction from the wheel hub during operation, and the handle (1) moves between a first and second position which first and second positions are interrelated in a V- shape.

3. A drive device according to claim 1 or 2, wherein the gear unit (7) comprises input means (7b) such as a gear wheel and output means (7a) such as a gear wheel where the input means (7b) are mechanically connected to the handle (1) and driven by the handle (1) whereas the output means (7a) are mechanically connected to a wheel of a manually operated wheelchair and drive this wheel.

4. A drive device according to claim 3, wherein the gear unit (7) is configured to change the direction of rotation in such a way that the input means (7b) are rotated in a first rotational direction and output means (7a) are rotated in a second rotational direction, and intermediate means (7c) translate the rotational direction of the input means (7b) into the rotational direction of the output means (7a).

5. A drive device according to any previous claim, wherein the gear unit (7) comprising input means (7b) and output means (7a) is a bevel gear or a planet gear.

6. A drive device according to any previous claim, wherein the gear or gear part (7a) constitutes a part of the wheel of the wheelchair and is coaxial with a rotatably coupling part of the handle part (A) during operation i.e. when the corresponding primary (5) and secondary (6) fastening means are joined.

7. A drive device according to any one of claim 1-5, wherein the gear or gear part (7a) constitutes a part of the handle part (A) and is positioned coaxial with the stationary rotation axis (4) of the wheelchair wheel during operation, i.e. when the corresponding primary (5) and secondary (6) fastening means are joined.

8. A drive device according to any previous claim, wherein the corresponding primary and secondary fastening means (5, 6) of respectively the handle part (A) and the fixed part (B) are constituted by magnets either partly or completely.

9. A drive device according to any previous claim, wherein the corresponding primary and secondary fastening means (5, 6) of respectively the handle part (A) and the fixed part (B) are constituted by releasable click-parts.

10. A drive device according to any previous claim, wherein the primary fastening means (5) are configured to attach the handle part (A) to an outer end or outer surface of the wheel or wheel hub where "outer" means that the end or surface of the wheel or wheel hub faces away from a seated user.

11. A drive device according to any previous claim, wherein the handle part (A) extends from a central point of the wheel to a length of minimum 0,20 m, or a length of minimum of 0,30 m, and / or to a maximum of 0,90 m, or at maximum 0,80m or at maximum 0,70 m.

12. A drive device according to any previous claim, wherein the handle part (A) comprises a switch mechanism (8, 9, 10) configured to switch between at least two, at least three or more different operational modes, which operational modes are defined as- a first mode where the wheel is rotated, and the wheelchair is propelled forward when the handle (1) is moved in the first direction, whereas there is no load on the handle (1) when the handle (1) is moved in the second direction, and- a second mode where the wheel is rotated, and the wheelchair is propelled backward when the handle (1) is moved in the second direction, whereas there is no load on the handle (1) when the handle (1) is moved in the first direction.

13. A drive device according to claim 12, wherein the first direction is backward i.e. the handle (1) is pulled towards the user, and the second direction is forward i.e. the handle (1) is pushed away from the user.

14. A drive device according to claim 12 or 13, wherein the switch mechanism (8, 9, 10) is configured to switch between at least three or more different operational modes, where a third operational mode is a neutral mode in which mode the wheel is not rotated by moving the handle (1), neither when the handle (1) is moved in the first direction, nor when the handle (1) is moved in the second direction.

15. A drive device according to claim 12 or 13 or 14, wherein the switch mechanism comprises locking means (10) and an actuating mechanism (9), which actuating mechanism (9) is configured to be activated by the user and either activate (lock) or deactivate (unlock) the locking mechanism (10) to choose an operational mode.

16. A drive device according to claim 12 or 13 or 14 or 15, wherein the switch mechanism comprises at least two rotating parts (8) each rotating part (8) configured to be locked or unlocked by locking means (10).

17. A drive device according to claim 16, wherein at least one of or all the rotating part (8) comprises either a one-way clutch or a rachet mechanism.

18. A drive device according to claim 16 or 17, wherein the at least two rotating parts (8) are positioned on either one common rotation axis (16) or on two separate rotation axis (16).

19. A wheelchair comprising a fixed part (B) fixed to or constituting a part of a wheel hub or a wheel and comprising secondary fastening means (6) corresponding to primary fastening means (5) of a handle part (A) of a drive device according to one of the claims 1-18.

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